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2,014 results on '"Laboratoire sols, solides, structures - risques [Grenoble] (3SR)"'

1. Modelling of cyclic visco-elasto-plastic behaviour of coated woven fabrics under biaxial loading and finite strain

Author

Arnaud Blaise, W. Dib, G. Bles, A. Tourabi, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Recherche Dupuy de Lôme (IRDL), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Centre National de la Recherche Scientifique (CNRS), Mécanique et Couplages Multiphysiques des Milieux Hétérogènes (CoMHet ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Mécanique et Couplages Multiphysiques des Milieux Hétérogènes (CoMHet), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
Weaving, Finite element method, Materials science, Synthetic fibres, 020101 civil engineering, 02 engineering and technology, Synthetic fibers, engineering.material, Non Newtonian flow, 0201 civil engineering, Coating, Woven fabric, Yarn, [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], Cyclic loading, General Materials Science, Cyclic loads, Composite material, Anisotropy, business.industry, Textiles, Applied Mathematics, Mechanical Engineering, Elasto plastic, Behaviour of sailcloth materials, Structural engineering, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Synthetic fiber, Mechanics of Materials, Modeling and Simulation, Finite strain theory, engineering, ABAQUS, 0210 nano-technology, business, Finite element code, Plastic coatings
Abstract

International audience; This paper deals with the modelling of the mechanical behaviour of coated woven fabric. The proposed model takes into account the individual behaviours of the yarns, the coating and their interactions including the influence of the angle variation between warp and weft yarns. This model is able to describe simultaneously the non-Newtonian viscous behaviour, the time-independent irreversibility, the anisotropy and the cyclic loading behaviour. The model was implemented in the finite element code ABAQUS and enables calculations on structures such as complete sails.

Published
2018

2. Large-scale tests to assess the efficiency of a geosynthetic reinforcement over a cavity

Author

Bekoin Francis Guillaume Tano, F. Olivier, S. S. Coulibaly, Nathalie Touze-Foltz, Guillaume Stoltz, Daniel Dias, J. Bruhier, Hydrosystèmes et Bioprocédés (UR HBAN), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), GéoMécanique, Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), aucun, Ecogeos, Hydrosystèmes et bioprocédés (UR HBAN), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), ECOGEOS ARRAS FRA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), HUESKER FRANCE GRESSWILLER FRA, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Aix Marseille Université (AMU)

Subjects
Scale (ratio), [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, 0211 other engineering and technologies, TOTAL PRESSURE CELL, 020101 civil engineering, 02 engineering and technology, Geotechnical Engineering and Engineering Geology, GEOSYNTHETICS, STRAIN GAUGE, REINFORCEMENT, 0201 civil engineering, LARGE-SCALE TEST, [SDE]Environmental Sciences, CAVITY, Geotechnical engineering, Geosynthetics, Reinforcement, ComputingMilieux_MISCELLANEOUS, Geology, Strain gauge, 021101 geological & geomatics engineering, Civil and Structural Engineering
Abstract

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE [ADD1_IRSTEA]Hydrosystèmes et risques naturels [Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE [ADD1_IRSTEA]Hydrosystèmes et risques naturels; International audience; This report presents a new large-scale test apparatus (LSTA) developed to assess the efficiency of a geosynthetic reinforcement for the limitation of deformations of a geosynthetic lining system (GLS) over a 0.5 m wide cavity. Two experiments were conducted. The first one involved a geosynthetic clay liner, a nonwoven needle-punched geotextile and a high-density polyethylene geomembrane. For the second experiment, a 50 kN/m polyvinyl alcohol geogrid was embedded within the sand layer below the geosynthetic clay liner to provide reinforcement above the cavity. An overburden pressure varying from 10 to 100 kPa was applied to the top of the GLS. Strain gauges were used to measure the strain within the geogrid and the geomembrane. The results proved that the 50 kN/m geogrid reinforcement beneath the geomembrane reduced the maximum strain within the geomembrane, compared to the case where the geomembrane was unreinforced, by 25% on average. The results showed that the overall strain within the geomembrane was 31% to 42% less than that of the geogrid above the cavity. Finally, the results showed that the spatial distribution of the strain within the geomembrane and that of the geogrid differed because of a conical shape of the collapsed zone.

Published
2018

3. Development of an excavatability test for backfill materials: numerical and experimental studies

Author

Sylvain Murgier, François de Larrard, Caroline Morin, Christophe Dano, Michel Hardy, Hélène Dumontet, Thierry Sedran, CERIB, Département Matériaux (IFSTTAR/MAT), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-PRES Université Nantes Angers Le Mans (UNAM), Direction scientifique (IFSTTAR/DS), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Institut Jean le Rond d'Alembert (DALEMBERT), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Unité de Science du Sol (Orléans) (URSols), Institut National de la Recherche Agronomique (INRA), EDF/CEIDRE, EDF (EDF)-CEIDRE, GéoMécanique, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut Jean Le Rond d'Alembert (DALEMBERT), Unité de Science du Sol, INRA, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
excavatability, Engineering, business.industry, impact energy, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, 0211 other engineering and technologies, punching test, 02 engineering and technology, Geotechnical Engineering and Engineering Geology, Test (assessment), Excavatability, Laboratory test, 021105 building & construction, cement-treated materials, Forensic engineering, Geotechnical engineering, Cementitious, repeatability, business, Punching, 021101 geological & geomatics engineering, Civil and Structural Engineering
Abstract

International audience; This paper describes research done on a new testing device including its laboratory test procedure; namely, a laboratory punching test for cementitious backfill materials that evaluates their excavatability with a pick. Three-dimensional and two-dimensional numerical studies using a finite element method were carried out according to calibrated parameters of the material obtained by triaxial tests. This made it possible to study the behavior of the backfill material under action induced by a tool (a pick) as well as to optimize the geometry of the punching test specimen. This paper provides detailed information and results for the experimental study of this laboratory test. Attention was particularly focused on energy relating to displacement as well as types of ruptures. The behavior of these types of materials was found to be greatly influenced by gravel in the material. Repeatability of the test was also studied. Finally, a method for this punching test of backfill materials is also provided.

Published
2018

4. DEM Modeling of a Flexible Barrier Impacted by a Dry Granular Flow

Author

Adel Albaba, Bruno Chareyre, François Nicot, Stéphane Lambert, François Kneib, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), GéoMécanique, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Engineering, Flow (psychology), 0211 other engineering and technologies, 02 engineering and technology, 010502 geochemistry & geophysics, Granular material, 01 natural sciences, T Technology (General), Software, SD Forestry, Numerical modeling, Geotechnical engineering, Sensitivity (control systems), Granular flows, Mechanical interaction, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Civil and Structural Engineering, business.industry, DEM, Geology, Structural engineering, 15. Life on land, Flexible barriers, Geotechnical Engineering and Engineering Geology, Debris, Discrete element method, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of the structures [physics.class-ph], Impact, Flow conditions, Transmission (telecommunications), [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph], GB Physical geography, business
Abstract

International audience; Flexible barriers are widely used as protection structures against natural hazards in mountainous regions, in particular for containing granular materials such as debris flows, snow avalanches and rock slides. This article presents a discrete element method-based model developed in the aim of investigating the response of flexible barriers in such contexts. It allows for accounting for the peculiar mechanical and geometrical characteristics of both the granular flow and the barrier in a same framework, and with limited assumptions. The model, developed with YADE software, is described in detail, as well as its calibration. In particular, cables are modeled as continuous bodies. Besides, it naturally considers the sliding of rings along supporting cables. The model is then applied for a generic flexible barrier to demonstrate its capacities in accounting for the behavior of different components. A detailed analysis of the forces in the different components showed that energy dissipators (ED) had limited influence on total force applied to the barrier and retaining capacity, but greatly influenced the load transmission within the barrier and the force in anchors. A sensitivity analysis showed that the barrier's response significantly changes according to the choice of ED activation force and incoming flow conditions.

Published
2017

5. Numerical modelling to identify key factors controlling interface behaviour of geosynthetic lining systems

Author

Guillaume Stoltz, Bekoin Francis Guillaume Tano, Daniel Dias, Nathalie Touze-Foltz, F. Olivier, Sibille, Luc, Hydrosystèmes et Bioprocédés (UR HBAN), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), GéoMécanique, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), aucun, Ecogeos, Hydrosystèmes et bioprocédés (UR HBAN), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
021110 strategic, defence & security studies, Finite difference code, business.industry, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, 0211 other engineering and technologies, 02 engineering and technology, Structural engineering, Geotechnical Engineering and Engineering Geology, Strain softening, Key factors, Shear (geology), [SPI.GCIV.GEOTECH] Engineering Sciences [physics]/Civil Engineering/Géotechnique, Shear stress, Nonlinear stiffness, Geotechnical engineering, Geosynthetics, business, ComputingMilieux_MISCELLANEOUS, Geology, 021101 geological & geomatics engineering, Civil and Structural Engineering
Abstract

Geosynthetics have been extensively used in landfills as a lining system to prevent leachate infiltration into groundwater. In piggy-back landfill expansion (PBLE), consisting of building a new landfill over an existing one, a lining system is implemented between the old and new waste. In this context, interface failure (stability) and deformation (integrity) of the lining system should be considered for the design. Such stability and integrity mainly depend on the PBLE geometry and the mechanical properties of the geosynthetics. Comprehensive numerical modelling simulations were performed to show how these factors influence the shear stresses, shear displacements, translational stability and the axial strains/forces within the various geosynthetics. The numerical modelling was conducted using the finite difference code FLAC 2D, focusing on a typical PBLE and considering geosynthetic interface strain softening, the nonlinear stiffness of geosynthetics, and the differentiation between the compressive and tensile behaviours of geosynthetics. The simulations showed that the lateral length of the PBLE, the type of geomembrane (textured or smooth) and the level of the leachate table in new waste are the factors that most influenced the mechanical behaviour of the lining system and its stability. Finally, a parameter called the stability ratio was proposed as a complement to the traditional factor of safety, to analyse the progressive slippage along the geosynthetic interfaces. The numerical results indicated that interface failure concurrently begins at the rightmost part of the lower flat area of the PBLE and near the corner of the inner slope before spreading out to the left as backfilling progresses.

Published
2017

6. The dynamic response of prone-to-fall columns to ambient vibrations: comparison between measurements and numerical modelling

Author

Eric Larose, A. Capron, Denis Jongmans, Frédéric Donze, J. Valentin, Anne Mangeney, P. Bottelin, Laurent Baillet, Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), Institut de biologie et chimie des protéines [Lyon] (IBCP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), GéoMécanique, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interdisciplinaire de Recherche Impliquant la Géologie et la Mécanique (LIRIGM), Université Joseph Fourier - Grenoble 1 (UJF), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Laboratoire Central des Ponts et Chaussées (LCPC)-Institut des Sciences de la Terre (ISTerre), and Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)

Subjects
010504 meteorology & atmospheric sciences, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, Mechanics, Seismic noise, [SPI.GCIV.CH]Engineering Sciences [physics]/Civil Engineering/Construction hydraulique, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Geophysics, Geophysics, Geochemistry and Petrology, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, ComputingMilieux_MISCELLANEOUS, Geology, 0105 earth and related environmental sciences
Abstract

International audience; Seismic noise measurements (ambient vibrations) have been increasingly used in rock slope stability assessment for both investigation and monitoring purposes. Recent studies made on gravitational hazard revealed significant spectral amplification at given frequencies and polarization of the wave-field in the direction of maximum rock slope displacement. Different properties (resonance frequencies, polarization and spectral ratio amplitudes) can be derived from the spectral analysis of the seismic noise to characterize unstable rock masses. The objective here is to identify the dynamic parameters that could be used to gain information on prone-to-fall rock columns' geometry. To do so, the dynamic response of prone-to-fall columns to seismic noise has been studied on two different sites exhibiting cliff-like geometry. Dynamic parameters (main resonance frequency and spectral ratio amplitudes) that could characterize the column decoupling were extracted from seismic noise and their variations were studied taking into account the external environmental parameter fluctuations. Based on this analysis, a two-dimensional numerical model has been set up to assess the influence of the rear vertical fractures identified on both sites on the rock column motion response. Although a simple relation was found between spectral ratio amplitudes and the rock column slenderness, it turned out that the resonance frequency is more stable than the spectral ratio amplitudes to characterize this column decoupling, provided that the elastic properties of the column can be estimated. The study also revealed the effect of additional remote fractures on the dynamic parameters, which in turn could be used for detecting the presence of such discontinuities.

Published
2016

7. Strain and Flow Pathways in a Shale Fault Zone: An In-Situ Test of Fault Seal Integrity

Author

L. De Barros, R. Castilla, J. Durand, Pierre Henry, Pierre Dick, Frédéric-Victor Donzé, A. Tsopela, Yves Guglielmi, D. Neyens, Claude Gout, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'étude et de recherche sur les transferts et les interactions dans les sous-sols (IRSN/PSE-ENV/SEDRE/LETIS), Service des déchets radioactifs et des transferts dans la géosphère (IRSN/PSE-ENV/SEDRE), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), PSE-ENV/SEDRE/LETIS, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)

Subjects
Dilatant, Shearing (physics), geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Borehole, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Classification of discontinuities, Fault (geology), 010502 geochemistry & geophysics, 01 natural sciences, Volumetric flow rate, Permeability (earth sciences), Electrical resistivity and conductivity, [SDU]Sciences of the Universe [physics], [SDE]Environmental Sciences, Petrology, Geology, 0105 earth and related environmental sciences
Abstract

International audience; A series of small scale (decametric) injection tests were performed in a small fault at IRSN Tournemire underground laboratory in Toarcian shales. Pressure, induced strains and flow rate were monitored at the injection borehole. Monitoring systems comprising strain sensors and a resistivity streamer were installed in observation boreholes within the fluid invaded zone. A micro-seismic network was also deployed. This experiment shows complex interactions between flow and strain as both appear to be distributed between major discontinuities and the fracture network in the damage and core zones. Permeability variations can be approximated as exponential functions of fluid pressure, with different coefficients below and above a threshold, defining the Fracture Opening Pressure. Hydraulic opening is typically associated with dilatant shearing of fractures. However, the associated strain appears small and largely reversible. Rupture on the main fault plane is triggered after several hours of injection, resulting in a permanent change of flow pathways and flow rate. Numerical modeling based on these experimental results suggest fluid channeling along a fault zone could occur in the subcritical Coulomb regime without fault activation at the larger scale.

Published
2019

8. Preferential Growth of Force Network in Granular Media

Author

Félix Darve, Jérôme Duriez, François Nicot, Antoine Wautier, Richard Wan, Mehdi Pouragha, Department of Civil Engineering [Calgary], University of Calgary, Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Natural Sciences and Engineering Research Council of Canada STPGP 462988

Subjects
Dependency (UML), Materials science, 0211 other engineering and technologies, Complex system, General Physics and Astronomy, 02 engineering and technology, Mechanics, [PHYS.MECA]Physics [physics]/Mechanics [physics], Granular material, 01 natural sciences, Contact force, law.invention, Mechanism (engineering), Mechanics of Materials, law, 0103 physical sciences, General Materials Science, Current (fluid), Hydrostatic equilibrium, 010306 general physics, 021101 geological & geomatics engineering, Positive feedback
Abstract

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE [ADD1_IRSTEA]Hydrosystèmes et risques naturels; International audience; The paper studies the evolution of contact forces in granular materials as a preferential growth process whereby the incremental change in forces is proportional to their current values. Preferential growth of forces is depicted herein as a positive feedback process that enhances the heterogeneity in granular media over the course of loading. As an initial step, 2D discrete element simulations are performed to verify the hypothesis in the simpler case of hydrostatic loading, with an extension to deviatoric loading thereafter suggested. Not being predicated upon particularities of any mechanical model, the preferential growth mechanism reveals the commonality between the force network and other self-organized complex systems with dynamic interaction networks. The paper concludes with potential mechanical consequences such a dependency between current state and the incremental change entails.

Published
2019

9. A study of the mechanical response of polycrystalline ice subjected to dynamic tension loading using the spalling test technique

Author

Maurine Montagnat, Dominique Saletti, Victor Gouy, Pascal Forquin, David Georges, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), and Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, ice, Aerospace Engineering, 020101 civil engineering, Ocean Engineering, 02 engineering and technology, strain-rate sensitivity, [SPI.MECA.MSMECA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Materials and structures in mechanics [physics.class-ph], Sensitivity (explosives), 0201 civil engineering, spalling test, 0203 mechanical engineering, Ultimate tensile strength, Composite material, dynamic tensile strength, Safety, Risk, Reliability and Quality, Civil and Structural Engineering, Mechanical Engineering, Dynamic Tension, Strain rate, [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph], Spall, Cracking, 020303 mechanical engineering & transports, Mechanics of Materials, fracture, Automotive Engineering, Fracture (geology), Crystallite
Abstract

International audience; Highlights • The spalling test technique is conducted to study the dynamic tensile strength of polycrystalline ice. • The results show the sensitivity of the tensile strength to the applied strain rate (from 41 s − 1 to 271 s − 1). • Three indicators are proposed to assess the results based on an optical analysis, a measurement of the wave speed and an analysis of the transmitted pulse. • An increase of the cracking density with the strain rate is observed.

Published
2019

10. A multifiber Timoshenko beam with embedded discontinuities

Author

Nathan Benkemoun, Ibrahim Bitar, Stéphane Grange, Panagiotis Kotronis, Institut de Recherche en Génie Civil et Mécanique (GeM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université de Nantes - Faculté des Sciences et des Techniques, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
Physics, Timoshenko beam theory, Cantilever, Mechanical Engineering, Constitutive equation, 0211 other engineering and technologies, 02 engineering and technology, Mechanics, Classification of discontinuities, Numerical integration, [SPI.MAT]Engineering Sciences [physics]/Materials, 020303 mechanical engineering & transports, Discontinuity (geotechnical engineering), 0203 mechanical engineering, Mechanics of Materials, Displacement field, Cylinder stress, General Materials Science, 021101 geological & geomatics engineering
Abstract

International audience; An enhanced high order multifiber Timoshenko beam is introduced to simulate structural behavior up to failure. The beam is displacement based and geometrically linear, its section can be of arbitrary shape and a local constitutive law is assigned to each fiber. The Strong Discontinuity Approach is adopted to enhance the displacement field of the fibers to describe crack openings. The material behaviour at the discontinuity is characterized by a linear cohesive law linking the axial stress and the displacement jump. The variational formulation is presented in the context of the incompatible modes method and details are given on the corresponding computational procedure and the numerical integration of the constitutive laws. The simulation of the non linear behavior of a cantilever beam structure and of a reinforced concrete frame are provided to illustrate the performance of the novel enhanced high order multifiber Timoshenko beam.

Published
2019

11. Mean force and fluctuations on a wall immersed in a sheared granular flow

Author

Mohamed Naaim, Frédéric Dufour, François Kneib, Thierry Faug, Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), People Programme (Marie Curie Actions) of the EU 7th FP under REA : 622899, and ANR-11-LABX-0030,TEC XXI,Ingénierie de la Complexité : la mécanique et ses interfaces au service des enjeux sociétaux du 21iè(2011)

Subjects
Shearing (physics), Physics, [PHYS]Physics [physics], Inertial frame of reference, FORCE SUR UN MUR, Autocorrelation, Monotonic function, Mechanics, [PHYS.MECA]Physics [physics]/Mechanics [physics], Critical value, 01 natural sciences, Discrete element method, 010305 fluids & plasmas, Contact force, FLUCTUATIONS DE FORCE, Physics::Fluid Dynamics, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], 0103 physical sciences, 010306 general physics, Quasistatic process
Abstract

International audience; In a sheared and confined granular flow, the mean force and the force fluctuations on a rigid wall are studied by means of numerical simulations based on the discrete element method. An original periodic immersed-wall system is designed to investigate a wide range of confinement pressure and shearing velocity imposed at the top of the flow, considering different obstacle heights. The mean pressure on the wall relative to the confinement pressure is found to be a monotonic function of the boundary macroscopic inertial number which encapsulates the confinement pressure, the shearing velocity, and the thickness of the sheared layer above the wall. The one-to-one relation is slightly affected by the length of the granular system. The force fluctuations on the wall are quantified through the analysis of both the distributions of grain-wall contact forces and the autocorrelation of force time series. The distributions narrow as the boundary macroscopic inertial number decreases, moving from asymmetric log-normal shape to nearly Gaussian-type shape. That evolution of the grain-wall force distributions is accompanied at the lowest inertial numbers by the occurrence of a system memory in terms of the force transmitted to the wall, provided that the system length is not too large. Moreover, the distributions of grain-wall contact forces are unchanged when the inertial number is increased above a critical value. All those results allow to clearly identify the transitions from quasistatic to dense inertial, and from dense inertial to collisional, granular flow regimes.

Published
2019

12. Compressive Failure as a Critical Transition: Experimental Evidence and Mapping onto the Universality Class of Depinning

Author

David Amitrano, Chi-Cong Vu, Jérôme Weiss, Olivier Plé, Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire Interdisciplinaire de Recherche Impliquant la Géologie et la Mécanique (LIRIGM), Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut des Géosciences de l’Environnement (IGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), and Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Condensed Matter - Materials Science, Materials science, Statistical Mechanics (cond-mat.stat-mech), Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, General Physics and Astronomy, Landslide, Mechanics, Renormalization group, 01 natural sciences, Power law, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Acoustic emission, 13. Climate action, Sample size determination, 0103 physical sciences, Compressive failure, 010306 general physics, Porosity, Critical exponent, Condensed Matter - Statistical Mechanics, ComputingMilieux_MISCELLANEOUS
Abstract

Acoustic emission (AE) measurements performed during the compressive loading of concrete samples with three different microstructures (aggregate sizes and porosity) and four sample sizes revealed that failure is preceded by an acceleration of the rate of fracturing events, power law distributions of AE energies and durations near failure, and a divergence of the fracturing correlation length and time towards failure. This argues for an interpretation of compressive failure of disordered materials as a critical transition between an intact and a failed state. The associated critical exponents were found to be independent of sample size and microstructural disorder and close to mean-field depinning values. Although compressive failure differs from classical depinning in several respects, including the nature of the elastic redistribution kernel, an analogy between the two processes allows deriving (finite)-sizing effects on strength that match our extensive dataset. This critical interpretation of failure may have also important consequences in terms of natural hazards forecasting, such as volcanic eruptions, landslides, or cliff collapses., Comment: Supplementary Material included

Published
2019

13. Seismic analysis of RC structures using damage model and simplified modeling, 12th Canadian Conference on Earthquake Engineering

Author

Mazars, Jacky, Grange, Stéphane, Mazars, Jacky, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
[SPI]Engineering Sciences [physics], [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, [SPI] Engineering Sciences [physics], [SPI.GCIV.STRUCT] Engineering Sciences [physics]/Civil Engineering/Structures, [SPI.GCIV] Engineering Sciences [physics]/Civil Engineering, [SPI.GCIV.DV] Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2019

14. Orchard management and preferential flow in Andosols – comparing two kiwifruit orchards in New Zealand

Author

Alfonso Gastelum Strozzi, Lorenzo Spadini, Anne-Julie Tinet, P. Charrier, Céline Duwig, Marie Christine Morel, Karin Müller, Bioinformatics Institute, University of Auckland [Auckland]-AgResearch Ltd, Institut des Géosciences de l’Environnement (IGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire d'étude des transferts en hydrologie et environnement (LTHE), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Laboratoire Central des Ponts et Chaussées (LCPC)-Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
[SDE.MCG]Environmental Sciences/Global Changes, Soil Science, Soil science, 010501 environmental sciences, Environmental Science (miscellaneous), 01 natural sciences, soil architecture, Soil functions, TRACER, Porosity, 0105 earth and related environmental sciences, Earth-Surface Processes, X-ray computed tomography, 2. Zero hunger, Macropore, carbon, 04 agricultural and veterinary sciences, Soil carbon, 15. Life on land, kiwifruit orchard, Permeability (earth sciences), filtering function, [SDE]Environmental Sciences, Soil water, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Environmental science, Orchard
Abstract

Sustainable horticulture depends on the integrity of soil functions, which directly depend on soil architecture affecting aggregation, root growth, as well as liquid and gas permeability. We hypothesised that changes in soil architecture resulting from feedback mechanisms between management, soil organic carbon contents (SOC), biota and vegetation can be captured with X-ray computed tomography (CT), and that these affect the soil filtering function, which thus, can be manipulated through orchard management. We compared the transport of copper, a widely used fungicide, through intact soil cores from vine rows of kiwifruit orchards under organic and integrated management. We first derived 3D-macropore characteristics from CT-images, followed by leaching a pulse of copper and a tracer through the same cores. The organic orchard soil had a significantly higher SOC content than the integrated orchard soil, and this was positively correlated with total porosity. Macropores (>92µm) were larger with a higher connectivity, but significantly fewer in the organic than the integrated orchard soil. This resulted in a lower macroporosity and a better copper filtering capacity of the organic than the integrated orchard soil. Copper distribution was reasonably predicted when combining SOC contents, pH and macropore characteristics. Significant relationships between soil parameters and indicators of the strength of preferential flow verified that CT-derived macropore characteristics can be used to predict functional solute transport parameters. The relevance of our results and relationships observed between macropore characteristics, functional indicators of preferential flow and the fate of copper needs verification with samples representing more soils and sites.

Published
2019
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15. Quantitative prediction of discrete element models on complex loading paths

Author

Luc Sibille, Rodaina Aboul Hosn, Félix Darve, Pascal Villard, GéoMécanique, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
Stress path, soil constitutive behaviour, Rolling resistance, 0211 other engineering and technologies, Computational Mechanics, Monotonic function, 02 engineering and technology, 01 natural sciences, Stress (mechanics), true triaxial loading paths, Calibration, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, General Materials Science, 0101 mathematics, discrete element method, true triaxial apparatus, 021101 geological & geomatics engineering, Mathematics, Plane (geometry), [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, Mechanics, Geotechnical Engineering and Engineering Geology, Compression (physics), [SPI.GCIV.CH]Engineering Sciences [physics]/Civil Engineering/Construction hydraulique, 010101 applied mathematics, Mechanics of Materials, SPHERES
Abstract

International audience; The ability of discrete element models to describe quantitatively (and not only qualitatively) the constitutive behaviour of a dense sand is assessed in this paper. Two kinds of 3D discrete models are considered. Both consider spheres as elementary particles. Nevertheless the first model implements a contact law with rolling resistance whereas the second takes into account clumps made of two spheres. The discrete models are calibrated and validated from mechanical tests performed on a dense Hostun sand with a true triaxial apparatus. The calibration is carried out from axi-symmetric drained compression tests, while the validation is discussed from monotonic and cyclic stress proportional loading paths and from a circular stress path in the deviatoric stress plane. The quality of the predictions of the discrete models are evaluated by comparison with the predictions given with advanced phenomenological constitutive relations, mainly an incrementally non-linear relation. Predictions given by the discrete models are remarkable, particularly when it is put in perspective with respect to the very few number of mechanical tests required for their calibration. However, these results and conclusions were reached in enabling conditions and some limitations of such discrete models should be kept in mind.

Published
2019

16. Systematic Endoscopy 5 Years After Sleeve Gastrectomy Results in a High Rate of Barrett's Esophagus: Results of a Multicenter Study

Author

Marine Benois, Luigi Angrisani, Thierry Piche, Paola Iovino, Maud Robert, Antonio Iannelli, Lionel Sebastianelli, Mirto Foletto, Emmanuel Gizard, Antonella Santonicola, Marco Bisello, Nicolas Turrin, Laurent Bailly, Laurent Turchi, Geoffroy Vanbiervliet, Luigi Schiavo, Alice Albanese, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hospices Civils de Lyon (HCL), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Physiopathologie et biothérapie: cellules souches, développement et cancer, Institut National de la Santé et de la Recherche Médicale (INSERM), IFR50, Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Faculté de Médecine Nice, Centre méditerranéen de médecine moléculaire (C3M), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National de la Recherche Agronomique (INRA), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Faculté de Médecine Nice, and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Côte d'Azur (UCA)

Subjects
Male, Endocrinology, Diabetes and Metabolism, medicine.medical_treatment, [SDV]Life Sciences [q-bio], Gerd, Endocrinology, 0302 clinical medicine, Weight loss, Prevalence, Esophagitis, Barrett’s esophagus, Endoscopy, Digestive System, Sleeve gastrectomy, Adenocarcinoma, Bariatric surgery, Endoscopy, GERD, Surgery, Nutrition and Dietetics, medicine.diagnostic_test, Middle Aged, Obesity, Morbid, 3. Good health, Diabetes and Metabolism, medicine.anatomical_structure, Italy, Gastroesophageal Reflux, Female, 030211 gastroenterology & hepatology, France, medicine.symptom, Adult, Peptic Ulcer, medicine.medical_specialty, 030209 endocrinology & metabolism, Barrett Esophagus, 03 medical and health sciences, Barrett's esophagus, Gastrectomy, Weight Loss, medicine, Humans, Esophagus, business.industry, Reflux, Proton Pump Inhibitors, medicine.disease, Multicenter study, business, Follow-Up Studies
Abstract

BACKGROUND: Recent evidence has indicated an increased risk of Barrett's esophagus (BE) in the long term after sleeve gastrectomy (SG). AIM: The aim of the study is to investigate the spectrum of gastroesophageal reflux disease (GERD) symptoms as well as the prevalence of BE, at minimum 5 years after SG in patients who underwent SG in different bariatric centers of two countries: France and Italy. PATIENTS AND METHODS: Five high volume outpatient centers dedicated to bariatric surgery that routinely perform upper GI endoscopy before any bariatric procedures were invited to participate in the study. From January 2017 to June 2018, each center during scheduled postoperative evaluation after surgery asked a minimum 10 consecutive patients, which had performed SG at least 5 years before and with no evidence of BE preoperatively, to undergo another upper GI endoscopy. RESULTS: Ninety (66 F) consecutive patients were enrolled. The mean follow-up was 78 +/- 15 months, and the mean total body weight loss was 25 +/- 12%. The prevalence of BE was 18.8% with no significant difference among centers. Weight loss failure was significantly associated with BE (p \textless 0.01). The prevalence of GERD symptoms, erosive esophagitis, and the usage of PPIs increased from 22%, 10%, and 22% before the SG to 76%, 41%, and 52% at the time of follow-up, respectively (p \textless 0.05). CONCLUSIONS: This multicenter study show a high rate of BE at least 5 years after SG. Weight loss failure was significantly associated with BE. We suggest to provide systematic endoscopy in these patients to rule out this condition.

Published
2019

17. Experimental investigation of microstructural changes in soils eroded by suffusion using X-ray tomography

Author

Cong Doan Nguyen, Nadia Benahmed, Edward Andò, Luc Sibille, Pierre Philippe, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), GéoMécanique, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Ouvrages hydrauliques et hydrologie (UR OHAX), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Suffusion, 0211 other engineering and technologies, 02 engineering and technology, 01 natural sciences, Matrix (geology), Internal erosion, Earth and Planetary Sciences (miscellaneous), [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, Geotechnical engineering, 0101 mathematics, Microstructure, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, X-ray computed tomography, 010102 general mathematics, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, 15. Life on land, Geotechnical Engineering and Engineering Geology, [SPI.GCIV.CH]Engineering Sciences [physics]/Civil Engineering/Construction hydraulique, 6. Clean water, Void ratio, Hydraulic structure, Soil structure, Soil water, Erosion, Heterogeneity, Shear strength (discontinuity), Geology
Abstract

Internal erosion is a complex phenomenon which represents one of the main risks to the safety of earthen hydraulic structures such as embankment dams, dikes or levees. Its occurrence may cause instability and failure of these structures with consequences that can be dramatic. The specific mode of erosion by suffusion is the one characterized by seepage flow-induced erosion, and the subsequent migration of the finest soil particles through the surrounding soil matrix mostly constituted of large grains. Such a phenomenon can lead to a modification of the initial microstructure and, hence, to a change in the physical, hydraulic and mechanical properties of the soil. A direct comparison of the mechanical behaviour of soil before and after erosion is often used to investigate the impact of internal erosion on soil strength (shear strength at peak and critical state) using triaxial tests. However, the obtained results are somehow contradictory, as for instance in Chang’s study (Chang and Zhang in Geotech Test J 34(6):579–589, 2011), where it is concluded that the drained strength of eroded soil decreases compared to non-eroded soil, while both Xiao and Shwiyhat (Geotech Test J 35(6):890–900, 2012) and Ke and Takahashi (Geotech Test J 37(2):347–364, 2014) have come to the opposite conclusion. A plausible explanation of these contradictions might be attributed to the rather heterogeneous nature of the suffusion process and to the way the coarse and fine grains are rearranged afterwards leading to a heterogeneous soil structure, a point that, for now, is not taken into account, nor even mentioned, in the existing analyses. In the present study, X-ray computed tomography (X-ray CT) is used to follow the microstructure evolution of a granular soil during a suffusion test, and, therefore, to capture the induced microstructural changes. The images obtained from X-ray CT reveal indeed that fine particles erosion is obviously not homogeneous, highlighting the existence of preferential flow paths that lead to a heterogeneous sample in terms of fine particles, void ratio and inter-granular void ratio distribution.

Published
2019

18. Enhancement of a two-dimensional multifibre beam element in the case of reinforced concrete structures for taking into account the lateral confinement of concrete due to stirrups

Author

Stéphane Grange, Natalia Khoder, Yannick Sieffert, Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), ANR-11-RSNR-0022,SINAPS@,Séisme et Installation Nucléaire -Améliorer et Pérenniser la Sûreté(2011), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and SINAPS@ ANR-11-RSNR-0022,SINAPS@,SINAPS@: Séisme & Installations Nucléaires: Assurer et Pérenniser la Sûreté

Subjects
Environmental Engineering, Materials science, éléments finis, 020101 civil engineering, 02 engineering and technology, stirrups, 0201 civil engineering, 0203 mechanical engineering, Cyclic loading, Civil and Structural Engineering, business.industry, multifibre beam elements, béton armé, Structural engineering, Reinforced concrete, reinforced concrete, Finite element method, Transverse reinforcement, Transverse plane, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, 020303 mechanical engineering & transports, aciers transversaux, finite elements, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, business, élément poutre multifibre, Confinement
Abstract

International audience; To assess the seismic vulnerability of existing reinforced concrete structures, a large number of degrees of freedom is involved. Consequently, efficient numerical tools are required. In the case of slender elements, enhanced beam elements have been developed to try to introduce shear effects, but in these models, the transverse steel is sometimes taken into consideration with approximated manner or often not at all. However, as shown by some experimental tests, the amount of transverse reinforcement triggers significantly the behaviour of beam elements, especially under cyclic loading. Thus, the main goal of this work is to investigate solutions for an enhanced multifibre beam element accounting for vertical stretching of the cross section, occurring due to the presence of transverse reinforcement. The efficiency of the proposed modelling strategies is tested with results obtained from tension and flexure tests conducted on an elastic linear material. Moreover, the implementation of stirrups is verified by comparison with analytical analysis.; Pour déterminer la vulnérabilité sismique des structures existantes en béton armé, des méthodes de calcul numérique à l’échelle structurelle efficaces et suffisamment précises sont nécessaires. Dans le cas d’éléments poutres, les recherches actuelles concernent le développement de cinématiques enrichies pour mieux tenir compte de la déformation des sections. A cette échelle, des formulations permettent déjà de reproduire les déformations générées par le cisaillement. En revanche, concernant les cadres d’armatures, soit ils ne sont pas du tout considérés, soit ils ne permettent pas d’établir un véritable équilibre global de la section transversale permettant de calculer le confinement du béton. Cependant, comme le montrent certains essais expérimentaux, la quantité d’armatures transversales pilote d’une manière significative le comportement de ces poutres. Le travail présenté dans cet article propose un modèle poutre multifibre enrichi pour la prise en compte de l’effet de confinement du béton par les armatures transversales. Des déplacements transversaux additionnels permettent d’enrichir la cinématique de la section transversale pour calculer l’équilibre. Le modèle est dans un premier temps validé avec des tests simples et une loi de comportement élastique linéaire pour le matériau composant la section. De plus, l’implémentation des aciers transversaux est validée par une comparaison faite avec une analyse analytique.

Published
2019

19. Revisiting statistical size effects on compressive failure of heterogeneous materials, with a special focus on concrete

Author

Olivier Plé, Chi-Cong Vu, David Amitrano, Jérôme Weiss, Damien Vandembroucq, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire Interdisciplinaire de Recherche Impliquant la Géologie et la Mécanique (LIRIGM), Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Surface du Verre et Interfaces (SVI), Centre National de la Recherche Scientifique (CNRS), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut des Géosciences de l’Environnement (IGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Length scale, Series (mathematics), Mechanical Engineering, Structure (category theory), 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Compressive strength, Brittleness, Mechanics of Materials, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], 0103 physical sciences, Statistical physics, 010306 general physics, 0210 nano-technology, Focus (optics), Dimensioning, Independence (probability theory), ComputingMilieux_MISCELLANEOUS, Mathematics
Abstract

Size effects on mechanical strength, i.e. the fact that larger structures fail under lower stresses than smaller ones, already highlighted by Leonardo da Vinci and Edmee Mariotte centuries ago, remain nowadays a crucial problem to establish structural design rules and safety regulations from an upscaling of laboratory data. These size effects are generally explained either from a deterministic energetic approach that predicts a non-vanishing asymptotic strength but, by construction, does not account for fluctuations around the mean strength and their size dependence, or from a statistical approach based on the weakest-link theory that implies a vanishing strength towards large scales. We recently proposed an alternative framework based on an interpretation of compressive failure of heterogeneous materials as a critical transition from an intact to a failed state, which releases the underlying hypotheses of the weakest-link theory, pure brittleness and the independence of damage events, while predicting a non-vanishing asymptotic mean strength but vanishing intrinsic fluctuations at large scales. Here, from an extensive series of uniaxial compression experiments (527 tests) on concrete samples with four different sizes and three different microstructures, we demonstrate (i) the failure of the weakest-link theory in this case, and instead (ii) the pertinence of our critical framework to account for size effects on compressive strength of an emblematic quasibrittle material, concrete, in terms of average strength, associated fluctuations, and probability of failure. From a detailed analysis of the microstructural disorder of our materials, we show that the pore structure, rather than the concrete mix, plays a significant role on size effects on strength. In this framework, the asymptotic strength σ∞ becomes the most relevant, material-dependent parameter for the dimensioning of large-scale structures from an upscaling of small-scale laboratory mechanical tests. An additional parameter, homogeneous to a length scale, controls the size dependence of the relative fluctuations of the strength. These new results call for a re-evaluation of classical design rules and the establishment of safety regulations from laboratory data for the compressive loading of quasi-brittle materials like concrete.

Published
2018

20. Association between asthma and lung function in adolescents born very preterm: results of the EPIPAGE cohort study

Author

Catherine Arnaud, Jessica Rousseau, Laure Couderc, Alice Hadchouel, Jean-Christophe Rozé, Adèle Bellino, Christophe Delacourt, Marie Mittaine, Stéphane Marret, Pierre-Yves Ancel, Marie Verstraete, Didier Pinquier, Institut Mondor de recherche biomédicale (IMRB), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), CIC Plurithématique de Nantes, Institut National de la Santé et de la Recherche Médicale (INSERM)-Ministère des Affaires sociales et de la Santé-Direction générale de l'offre de soins (DGOS)-Centre hospitalier universitaire de Nantes (CHU Nantes), INSERM, U1027, Toulouse, France., Service de pédiatrie médicale et médecine de l'adolescent [Rouen], CHU Rouen, Normandie Université (NU)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Team 4 'NeoVasc' - INSERM U1245, Génomique et Médecine Personnalisée du Cancer et des Maladies Neuropsychiatriques (GPMCND), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Aix Marseille Université (AMU), Recherche Epidémiologique en Santé Périnatale et Santé des Femmes et des Enfants (UMR_S 953), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Descartes - Paris 5 (UPD5)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Sud - Paris 11 (UP11), Domaines Océaniques (LDO), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS), Team 4 NeoVasc - Region Team ERI 28 INSERM (Neovasc), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Epidémiologie et analyses en santé publique : risques, maladies chroniques et handicaps (LEASP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Necker Enfants-Malades (INEM - UM 111 (UMR 8253 / U1151)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Centre National de la Recherche Scientifique (CNRS)-Institut d'écologie et environnement-Observatoire des Sciences de l'Univers-Université de Brest (UBO)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
Male, 0301 basic medicine, Pulmonary and Respiratory Medicine, Pediatrics, medicine.medical_specialty, Adolescent, Term Birth, [SDV]Life Sciences [q-bio], 03 medical and health sciences, Sex Factors, 0302 clinical medicine, Forced Expiratory Volume, Humans, Medicine, Prospective Studies, Respiratory system, Child, ComputingMilieux_MISCELLANEOUS, Lung function, Bronchopulmonary Dysplasia, Respiratory Sounds, Asthma, business.industry, Confounding, paediatric asthma, medicine.disease, 3. Good health, respiratory tract diseases, Very preterm, 030104 developmental biology, Breath Tests, 030228 respiratory system, Bronchopulmonary dysplasia, Case-Control Studies, Child, Preschool, Cohort, Premature Birth, Female, Nitrogen Oxides, France, business, paediatric lung disaese, Cohort study
Abstract

Prematurity and bronchopulmonary dysplasia (BPD) affect long-term lung function. We studied the respiratory outcome of adolescents born very preterm and controls from the Etude EPIdémiologique sur les Petits Ages Gestationnels cohort and analysed their current lung function in relation to asthma symptoms (categorised in three age groups) from birth. In models including BPD, asthma at each age and confounding factors in the preterm group, BPD and preschool wheeze were the only independent variables associated with FEV1. Preschool wheeze is an independent factor associated with FEV1 impairment in adolescents born very preterm. These results highlight the need for optimal management of early respiratory symptoms in preterm-born infants.Trial registration numberResults, NCT01424553.

Published
2018

21. Real scale impact experiments on Bloc Armé® as facing of rockfall protection embankment

Author

Agathe Furet, Stéphane Lambert, Pascal Villard, Jean-Philippe Jarrin, Julien Lorentz, Lucas Meignan, Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Géolithe, GéoMécanique, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Géolithe Innov, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Bloc Armé®, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, impact, rockfall, real scale experiments, protection structure
Abstract

International audience; This article presents real-scale experiments aiming to improve the understanding of protection structure facing's response when it's subjected to dynamic loading. Here, we focus on the presentation of the test conditions and measurement methods and we introduce first experimental results.

Published
2018

22. Quartz trace-element composition by LA-ICP-MS as proxy for granite differentiation, hydrothermal episodes, and related mineralization: The Beauvoir Granite (Echassières district), France

Author

Stefano Salvi, Didier Béziat, Loïs Monnier, Jérémie Melleton, Yogan Monnier, Laurent Bailly, Sophie Gouy, Philippe Lach, Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), GeoRessources, Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), BRGM (French Geological Survey), CNRS (French National Center for Scientific Research), University of Toulouse, Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])

Subjects
Stockwork, 010504 meteorology & atmospheric sciences, Trace element, Geochemistry, Granite differentiation, Footprinting, Geology, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, 010502 geochemistry & geophysics, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, 01 natural sciences, Hydrothermal episodes, Rare-metal ore deposit, Leucogranite, Quartz trace chemistry, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Geochemistry and Petrology, Greisen, Fluid inclusions, Igneous differentiation, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Quartz, Chemical composition, 0105 earth and related environmental sciences
Abstract

International audience; Despite quartz being a ubiquitous mineral in the Earth's crust, only little is known about its trace chemical composition and whether and how this is influenced by the medium from which it precipitated. Using in-situLA-ICP-MS analysis, we investigated the trace element composition of several types of quartz from a magmatic-hydrothermal system in the Echassières district of the French Massif Central. This system consists of the Colettes granite, the Beauvoir rare-element granite, a W-bearing stockwork and dispersed mineralized veins. All of the elements tested (Li, Be, B, Na, Al, Ti, Ge, Rb, Sr, Nb, Sn, Sb, Ta, W)were detected in quartz from at least one sample. A rigorous multivariate statistical approach permitted to assign a specific chemical signature to each of the quartz groups that were recognized by petrographic observations. Differences among these groups were interpreted to reflect different sources or genetic evolutionary trends within magmatic and hydrothermally derived quartz groups. For example, the evolution of Al, Rb, Ge, Li and Ti, could be related to genetic processes such as the degree of magma differentiation and crystallization temperatures. Quartz from the W-stockwork, anterior to the Beauvoir leucogranite, clearly stands out from that related to the Beauvoir mineralization system, i.e.,the greisen facies and proximal Ta-Nb-Sn-W mineralized veins. It was also possible to demonstrate a similarity in composition, notably the Sb contents, between quartz from the greisen and from distal stibnite-bearing veins. In addition, elevated values of Sb, Sn as well as Li and Rb in quartz correspond to similarly high values of these elements in the rock, indicating that quartz trace chemistry can provide useful information for the mineralization potential of its host, at least for these elements. On the other hand, Nb, Ta and W are less reliable, as they occur mostly at very low levels in quartz, the highest values corresponding to samples that were not particularly enriched in these metals. A comparison of our quartz data with those from a similar granitic complex, at Cínovec (Czech Republic, Breiter et al., 2017a), shows a similar trend for the Ge/Ti ratio, reflecting magmatic differentiation. Conversely, the Al/Ti ratio values differ in the two complexes, the Al content of quartz from the various Cínovec granites being systematically lower than in quartz from Echassières. Nevertheless, caution must be taken when analyzing quartz for its trace element chemistry, as processes occurring during (i.e.,trapping of fluid inclusions and formation of zoning) and after crystal growth (i.e.,diffusion and alteration), can introduce heterogeneities thus affecting the original chemistry

Published
2018

23. Effect of dynamics on the Soil-geosynthetic interfaces used in reinforced rockfall embankments

Author

Ismail Benessalah, Stéphane Lambert, Pascal Villard, Ahmed Arab, Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), GéoMécanique, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Lambert, Stéphane

Subjects
discrete elements method, Numerical modelling, pull-out test, [SPI.GCIV.GEOTECH] Engineering Sciences [physics]/Civil Engineering/Géotechnique, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, rockfall embankment
Abstract

International audience; Among the various passive protection structures, embankments reinforced with horizontal inclusions are one of those capable of containing the blocks with the highest kinetic energies, e.g. exceeding 5000 kJ (Descoeudres, 1997). The design of such structures requires consideration of parameters related to the soil-geosynthetic interfaces during the impact by the block on the embankment. In spite of recent technological developments, the response of soil-geosynthetic interfaces under dynamic loading of impact type remains largely unknown. This issue is tentatively addressed based on a numerical study of the dynamic pull-out behaviour of a geotextile sheet embedded into soil, as in rockfall protection embankments.

Published
2018

24. Mécanique des mésostructures dans les matériaux granulaires bidimensionnels

Author

Huaxiang Zhu, Guillaume Veylon, Félix Darve, François Nicot, Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), GéoMécanique, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )

Subjects
Dilatant, Environmental Engineering, Materials science, 0211 other engineering and technologies, force-chain, 02 engineering and technology, Granular material, Instability, Meso scale, 0203 mechanical engineering, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, Force chain, ComputingMilieux_MISCELLANEOUS, Topology (chemistry), 021101 geological & geomatics engineering, Civil and Structural Engineering, Mesoscopic physics, Hexagonal crystal system, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, Mechanics, [SPI.GCIV.CH]Engineering Sciences [physics]/Civil Engineering/Construction hydraulique, failure, instability, 020303 mechanical engineering & transports, localisation, [SDE]Environmental Sciences, mesoscopic structure
Abstract

International audience; Macroscopic behaviours of granular materials derive from the fabric distribution and evolution. Two kinds of fabric in the meso-scale can be distinguished: column-like clusters, called force-chains, which carry a majority of the external loading; and the loop-like clusters, called meso-loops, cells enclosed inside by contact branches. Some significant features in themeso-scale and how they influence themacroscopic behaviour of granular materials are investigated under the drained biaxial loading path. Results show that: (1) the macroscopic mechanical performance of the granular material can be associated to the evolution of the proportions of L3 (meso-loops with 3 sides) and L6+ (meso-loops of number of side no less than 6); (2) there exists a single mesoscopic topology as the signature of the critical state of granular materials; (3) the force-chains adjacent area is the main source and contributor of the global dilatancy of the granular material.Moreover, the instability of the idealised hexagonal loop, as the representation of L6+, is analysed. It is shown that under a loading path with a constant confinement, it is possible to proceed an elastic buckling, if there is a sufficient high confining stress or a sufficient low α0 (the initial opening angle of the hexagon, initially controlling the elongation of it along the axial direction). α0 and the stiffness ratio kt /kn (the tangential stiffness over the normal stiffness) are found to be greatly influential to the instability of the hexagon, through influencing the Mohr–Coulomb line of the hexagon.

Published
2016

25. New continuous strain-based description of concrete's damage-permeability coupling

Author

Matthieu Briffaut, Benoit Masson, S. Dal Pont, Julien Baroth, M. Ezzedine El Dandachy, D.E.-M. Bouhjiti, Frédéric Dufour, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), GéoMécanique, EDF (EDF), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
Materials science, strain-based permeability model, cracking, 0211 other engineering and technologies, Computational Mechanics, 02 engineering and technology, Geotechnical Engineering and Engineering Geology, Finite element method, [SPI.MAT]Engineering Sciences [physics]/Materials, regularization, Permeability (earth sciences), Cracking, Mechanics of Materials, 021105 building & construction, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, concrete, finite elements, General Materials Science, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, Composite material, strain‐based permeability model, [SPI.GCIV.GCN]Engineering Sciences [physics]/Civil Engineering/Génie civil nucléaire, 021101 geological & geomatics engineering
Abstract

International audience; This contribution aims at improving the finite element modelling of concrete's damage‐permeability coupling using continuous and elastic‐based damage approaches. With this aim in view, a review of existing local and nonlocal damage formulations is performed showing how they differ in terms of damage estimation, crack propagation, and spatial discretization restrictions (when the energy‐based Hillerborg criterion is applied). Another critical review of damage‐based permeability laws is achieved to pinpoint their limitations. Indeed, the use of a bounded and strictly increasing damage variable does not allow (1) an accurate description of permeability in the presence of macrocracks that are physically unbounded and (2) a proper description of the permeability decrease as those macrocracks are closed. Accordingly, a new strain‐based permeability law is suggested. Its analytical validation is based on the BIPEDE tensile test for one loading‐unloading cycle. This new formulation intends to enhance the predictiveness of damage‐permeability coupling models leading to a better assessment of large structure's durability and serviceability.

Published
2018

26. Coordinate free nonlinear incremental discrete mechanics

Author

Félix Darve, Noël Challamel, Jean Lerbet, François Nicot, Informatique, Biologie Intégrative et Systèmes Complexes (IBISC), Université d'Évry-Val-d'Essonne (UEVE), Institut de Recherche Dupuy de Lôme (IRDL), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Centre National de la Recherche Scientifique (CNRS), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), GéoMécanique, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Fiber bundle, Computer science, Applied Mathematics, Mathematical analysis, Connection (vector bundle), Transversality, Computational Mechanics, Vector bundle, 02 engineering and technology, Kinematics, [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph], 01 natural sciences, 010101 applied mathematics, Section (fiber bundle), Nonlinear system, Coordinate-free, 020303 mechanical engineering & transports, 0203 mechanical engineering, Kinematic structural stability, Cotangent bundle, Coordinate free approach, 0101 mathematics
Abstract

[Departement_IRSTEA]Eaux [ADD1_IRSTEA]Hydrosystèmes et risques naturels; International audience; In this paper we extend the Kinematic Structural Stability (KISS) issues obtained in the punctual linear case to a full non linear framework. Kinematic Structural Stability (KISS) refers to the stability of conservative or non-conservative elastic systems under kinematic constraints. We revisite and sometimes introduce some new mechanical and geometrically-related concepts, using the systematic language of vector bundles: transversality-stability, tangent stiffness tensor, loading paths and KISS. We bring an intrinsic geometrical meaning to these concepts and we extend the main results to a general nonlinear framework. The lack of connection on the configuration manifold in order to make derivatives of sections is bypassed thanks to the key rule of the nil section of the cotangent bundle. Two mechanical examples illustrate the interest of the new concepts, namely a discrete nonconservative elastic system under non-conservative loading (Ziegler's column) and, in more details, a four-sphere granular system with nonconservative interactions called diamond pattern.

Published
2018

27. Effects of Suffusion on the Soil’s Mechanical Behavior: Experimental Investigations

Author

Nadia Benahmed, Bruno Chareyre, Cong Doan Nguyen, Luc Sibille, Rodaina Aboul Hosn, Pierre Philippe, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Ouvrages hydrauliques et hydrologie (UR OHAX), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), GéoMécanique, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Stéphane Bonelli, Cristina Jommi, Donatella Sterpi, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Shearing (physics), [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, 0211 other engineering and technologies, 02 engineering and technology, 15. Life on land, [SPI.GCIV.CH]Engineering Sciences [physics]/Civil Engineering/Construction hydraulique, 010502 geochemistry & geophysics, Triaxial shear test, 01 natural sciences, Void ratio, Soil water, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, Geotechnical engineering, Triaxial compression, ComputingMilieux_MISCELLANEOUS, Geology, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Permeameter
Abstract

This study presents an experimental approach to investigate the impact of suffusion on the soil’s mechanical properties. A newly developed suffusion permeameter is used allowing separate erosion and mechanical tests. The effect of the initial density of the soil on the erosion process is examined. Thereafter, the influence of suffusion on the mechanical properties of the soil is investigated through drained and undrained monotonic triaxial compression tests. The results suggest that the shear strength of eroded soils may either decrease or increase or even may not be affected depending, among others, on the soil’s initial density. In addition, in all cases, slightly more dilative volumetric deformations seem to occur during shearing after erosion. Understanding the mechanical behavior of eroded soils depends on the combined effect of the global void ratio, the inter-granular void ratio and the final fines content after suffusion. Taking into account such a combined effect, an approach to estimate the shear strength of eroded soils is proposed.

Published
2018

28. Sûreté des barrages-voûtes existants

Author

Andrian, F., Bourdarot, E., Carrere, Audrey, Carvajal, C., Castanier, G., Couturier, B., Emeriault, F., Fabre, J.P., Fournie, Y., Hoonakker, M., Jellouli, M., Molin, X., Noret, C., Ousset, I., Prévôt, G., Robbe, E., Tardieu, B., Yziquel, A., Agresti, P., Roy, M., Coyne et Bellier, Tractebel engineering, Artelia Eau & Environnement [Echirolles], Artelia Eau & Environnement [Lyon], EDF (EDF), Ouvrages hydrauliques et hydrologie (UR OHAX), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Comité Technique Permanent des Barrages et Ouvrages Hydrauliques (CTPBOH), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), GéoMécanique, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Société Hydro-Electrique du Midi, Ministère de la Transition Ecologique et Solidaire (MTES), Bureau d'Etude Technique et de Contrôle des Grands Barrages (BETCGB), Ministère de l'Ecologie, de l'Energie du Développement Durable et de la Mer, ISL ingénieries, Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Consultant, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), SHEM FRA, Ministère de l'Ecologie, du Développement durable et du Transport, ISL, TRACTEBEL FRA, Irstea Publications, Migration, Ousset, Isabelle, and Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Aix Marseille Université (AMU)

Subjects
[SDE] Environmental Sciences, Arch-Dam, Barrage-voûte, BARRAGE-VOUTE, Monitoring, Performance, [SPI.GCIV.STRUCT] Engineering Sciences [physics]/Civil Engineering/Structures, Fondation, MODELE NUMERIQUE, Comportement, Concrete abutment, [SPI.GCIV.CH]Engineering Sciences [physics]/Civil Engineering/Construction hydraulique, Numerical model, Modèle numérique, Auscultation, [SDE]Environmental Sciences, CULEE, Culée, Foundation, Behaviour, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, [SPI.GCIV.CH] Engineering Sciences [physics]/Civil Engineering/Construction hydraulique
Abstract

In France we have about a hundred arch dams, essentially built between 1935 and 1980. These elegant, often majestic, structures testify to the knowledge of a generation of brilliant engineers. These engineers dared to draw pure and thin lines by optimizing the material placement to reconcile the structures safety with the projects costs. The mechanical operating mode ideally depends on the transmission of the efforts to their foundation by mobilizing arch effects. So it seems safe provided that the rock supports resist. In practice the behavior of these structures is complex, especially for geometries which are far from the standard design : arch dams settled in wide or expanded flat-bottom valleys, unfavourable slopes of banks. Due to the number of projects becoming scarce (set apart in some countries), it is essential to assess the safety of existing dams taking into account incidents and accidents analysis of these structures, as well as experiences gained through their behaviour analysis carried out for more than 50 years. These experimental lessons allow identifying the main failure modes, by distinguishing what come from a normal adaptation of the structure, from located cracks due to structure hyperstatic design, or from more global mechanisms. The present development of risk analyses and the regulatory requirements to take into account low frequency events require the search for analysis methods and if necessary for solutions (monitoring, remedial works) adapted to possible failure kinematics. In this context, a workgroup of the French Committee of Dams and Reservoirs, consisting of experts coming from consulting firms, operational groups and monitoring department, has introduced an approach centered on the analysis of the existing arch dams portfolio. This article presents the first results in terms of recommendations of behaviour analyses, failure modes, performance criteria and adapted monitoring. In addition, Coyne and Bellier / Tractebel and Artelia, two French engineering offices present their innovative practices on two specific topics, respectively: - a modelling of abutments through three examples ; - a modelling taking into account the loading history on structures by "cyclic calculations"., La France possède un parc d'une centaine de barrages-voûtes, construites essentiellement entre 1935 et 1980. Ouvrages élégants, souvent majestueux, ils témoignent du savoir-faire d'une génération d'ingénieurs brillants qui ont osé dessiner des lignes pures et minces en optimisant le placement de la matière pour concilier la sûreté des structures avec l'économie des projets. Le mode de fonctionnement mécanique des voûtes, reposant idéalement sur la transmission des efforts à leur fondation par la mobilisation des effets d'arcs, apparaît sûr à condition que les appuis rocheux résistent. Dans la pratique le comportement de ces ouvrages est complexe, surtout pour des géométries qui s'éloignent du dimensionnement standard : voûtes implantées dans des vallées larges ou à fond plat étendu, inclinaisons défavorables des rives. Le nombre de projets se raréfiant (mis à part quelques pays), il est primordial d'appuyer l'appréciation de la sûreté des barrages existants sur l'incidentologie et l'accidentologie de ces ouvrages, ainsi que sur l'analyse comportementale pratiquée depuis plus de 50 ans. Cet enseignement expérimental permet d'identifier les principaux mécanismes de défaillance, en distinguant ce qui relève d'une adaptation normale de l'ouvrage, de processus de rupture localisée liés à l'hyperstaticité des structures, ou de mécanismes plus globaux. Le développement actuel des analyses de risques, et l'évolution des réglementations visant à prendre en compte des événements d'occurrence très faibles, imposent la recherche de méthodes d'analyse et le cas échéant de solutions (surveillance, confortements) adaptées aux cinématiques de ruptures possibles. La démarche initiée par un groupe de travail du Comité Français des Barrages et Réservoirs composé d'experts de l'ingénierie, de l'exploitation et du contrôle des voûtes, centrée sur l'analyse du parc existant de voûtes, s'inscrit dans ce cadre. L'article présente les premiers résultats en termes de recommandations d'analyses comportementales, de scénarii de défaillances, de critères de performance, de surveillance adaptée. En plus de la présentation des travaux du groupe de travail, Coyne et Bellier/Tractebel et Artelia, deux bureaux d'études français présentent leurs pratiques innovantes sur deux sujets particuliers, respectivement : - une méthode de modélisation des culées au travers de trois exemples ; - une modélisation tenant compte de l'historique de chargements des ouvrages par des « calculs cycliques »

Published
2018

29. Analysis of cone penetration tests in snow with X-ray tomography

Author

Peinke, Isabel, Hagenmuller, Pascal, Andò, Edward, Flin, Frédéric, Chambon, Guillaume, Roulle, Jacques, Centre d'Etudes de la Neige (CEN), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Météo France-Centre National de la Recherche Scientifique (CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

30. Incidence de la microstructure sur la topologie du domaine de bifurcation des matériaux granulaires

Author

Huaxiang Zhu, Guillaume Veylon, Félix Darve, François Nicot, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), GéoMécanique, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Aix Marseille Université (AMU), DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING UNIVERSITY. OF MACAU CHN, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), French Research Network MeGe : GDR CNRS 3176/2340, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)

Subjects
Materials science, INSTABILITY, 0211 other engineering and technologies, BIFURCATION DOMAIN, 02 engineering and technology, Granular material, Domain (software engineering), 0203 mechanical engineering, Geomechanics, GRAIN LOOPS, GRANULAR MATERIALS, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, Topology (chemistry), Bifurcation, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, Mesoscopic physics, Mechanical Engineering, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, Mechanics, Microstructure, [SPI.GCIV.CH]Engineering Sciences [physics]/Civil Engineering/Construction hydraulique, 020303 mechanical engineering & transports, Mechanics of Materials, [SDE]Environmental Sciences, MICROSTRUCTURE
Abstract

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE [ADD1_IRSTEA]Hydrosystèmes et risques naturels [Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE [ADD1_IRSTEA]Hydrosystèmes et risques naturels; International audience; The detection of bifurcation in granular soils is a major concern in geomechanics. Recent advances in geomechanics have highlighted the key role played by the mesoscopic structures composed of grain loops in the stability of granular media. Based on an elementary grain loop pattern, this paper investigates the influence of the microstructure on the bifurcation domain topology at the mesoscopic scale. This study shows that, at the mesoscopic scale, the bifurcation domain cannot be consistently defined in terms of the stress state only. Expressed in a stress-microstructure space, the bifurcation domain becomes invariant with the contact regime, the initial microstructure, and the loading path. It is also shown that the microstructural anisotropy is as determinant as the stress state with respect to the bifurcation domain topology. Finally, the mechanical and volumetric behaviours of the granular assembly are shown to be correlated through a proper microstructural variable.

Published
2018

31. Three dimensional measurements of the deformation of snow induced by a cone penetration test

Author

Peinke, Isabel, Hagenmuller, Pascal, Andò, Edward, Flin, Frédéric, Chambon, Guillaume, Roulle, Jacques, Centre d'Etudes de la Neige (CEN), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), GéoMécanique, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Météo France-Centre National de la Recherche Scientifique (CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

32. Simplified Modeling Strategy for the Thermomechanical Analysis of Massive Reinforced Concrete Structures at an Early Age

Author

Jacky Mazars, Matthieu Briffaut, Stéphane Grange, Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Work (thermodynamics), Discretization, Computer science, 0211 other engineering and technologies, 020101 civil engineering, early age, 02 engineering and technology, Residual, reinforced concrete, THM modeling, damage modeling, scale effect, lcsh:Technology, 0201 civil engineering, lcsh:Chemistry, 021105 building & construction, General Materials Science, Instrumentation, lcsh:QH301-705.5, Shrinkage, Weibull distribution, Fluid Flow and Transfer Processes, business.industry, lcsh:T, Process Chemistry and Technology, General Engineering, Structural engineering, Reinforced concrete, lcsh:QC1-999, Computer Science Applications, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of the structures [physics.class-ph], lcsh:Biology (General), lcsh:QD1-999, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph], lcsh:TA1-2040, Thermomechanical analysis, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, business, lcsh:Engineering (General). Civil engineering (General), Beam (structure), lcsh:Physics
Abstract

International audience; The objective of this work is to propose a comprehensive and efficient modeling approach to simulate the entire loading program of the RG8 test (both the restrained shrinkage and mechanical parts) performed within the framework of the French national program CEOS.fr. This effort was made possible by introducing a multi-fiber beam discretization that included a thermomechanical model coupled with a unilateral concrete damage model. Due to the massiveness of the test structure, the scale effect needed to be taken into account. This step could be accomplished through use of a Weibull law. Extensive results were obtained during the experiment, some of which focused on deformations and forces developed in the structure by restrained shrinkage, the times of crack appearance and opening, and the consequences of damage sustained on the residual mechanical performance of the beam. A comparison with calculation output has demonstrated the ability of our modeling approach to simulate phenomena at both global and local levels, thus confirming the relevance of model choices made.

Published
2018

33. Simplified modeling strategy for the thermo-mechanical analysis of massive reinforced concrete structures at early age

Author

Mazars, Jacky, Grange, Stéphane, Briffaut, Matthieu, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Grange, Stéphane

Subjects
[SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, [SPI.GCIV] Engineering Sciences [physics]/Civil Engineering, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

34. Introduction of shear warping in fibre beam elements for the computation of the nonlinear behaviour of concrete beams

Author

Sophie Capdevielle, Frédéric Dufour, Cédric Desprez, Stéphane Grange, Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Sécurité et Durabilité des Ouvrages d'Art (IFSTTAR/MAST/SDOA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Capdevielle, Sophie, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Materials science, Concrete beams, business.industry, Computation, Linear elasticity, [SPI.GCIV.STRUCT] Engineering Sciences [physics]/Civil Engineering/Structures, Torsion (mechanics), 02 engineering and technology, Structural engineering, 01 natural sciences, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of the structures [physics.class-ph], 010101 applied mathematics, Nonlinear system, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, 020303 mechanical engineering & transports, 0203 mechanical engineering, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph], Transverse shear, [SPI.GCIV] Engineering Sciences [physics]/Civil Engineering, [SPI.MECA.STRU] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph], [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, 0101 mathematics, Image warping, business
Abstract

International audience; The present paper deals with modelling the nonlinear behaviour of concrete using the fibre element method. Proved to be efficient for slender structural elements mainly subject to normal stresses, the method lacks in accuracy when modelling the effect of shear. The present contribution proposes to enhanced a Timoshenko fibre beam element by adding shear warping deformations in the formulation. Transverse shear as well as torsion warping is taken into account, enabling the computation of the response to a complex loading. Warping degrees of freedom are computed simultaneously with the beam degrees of freedom by a fully implicit solution procedure. Concrete is modelled using a 3D damage model. Due to the coupling of warping and global beam degrees of freedom, the warping displacements in the beam element can evolve with the evolution of concrete damage. The beam element enhancement is validated at the cross-section scale considering a linear elastic behaviour. Enhanced beam elements are then used to model experimentally-tested structural elements. Both the linear and non-linear parts of the structural response are investigated.

Published
2018

35. Enhancement of multifiber beam elements in the case of reinforced concrete structures for taking into account the lateral confinement of concrete due to stirrup

Author

Natalia Khoder, Stéphane Grange, Yannick Sieffert, Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Sieffert, Yannick, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), ECN/UN, and Grange, Stéphane

Subjects
Materials science, [SPI.GCIV.STRUCT] Engineering Sciences [physics]/Civil Engineering/Structures, 0211 other engineering and technologies, 02 engineering and technology, Finite Elements, 010502 geochemistry & geophysics, 01 natural sciences, Multifiber Beam Elements, Stirrups, Cyclic loading, 0101 mathematics, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, business.industry, Structural engineering, Reinforced concrete, Stirrup, Transverse reinforcement, 010101 applied mathematics, Transverse plane, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Shear (geology), [SPI.GCIV] Engineering Sciences [physics]/Civil Engineering, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, business, Reinforced Concrete, Confinement
Abstract

Pour déterminer la vulnérabilité sismique des structures existantes en béton armé, des méthodes de calcul numérique à l’échelle structurelle efficaces et suffisamment précises sont nécessaires. Dans le cas d’éléments poutres, les recherches actuelles concernent le développement de cinématiques enrichies pour mieux tenir compte de la déformée des sections. A cette échelle, des formulations permettent déjà de reproduire les déformations de cisaillement. En revanche, concernant les cadres d’armatures, soit ils ne sont pas du tout considérés, soit ils ne permettent pas d’établir un véritable équilibre global de la section transversale permettant de calculer le confinement du béton. Cependant, comme le montrent certains essais expérimentaux, la quantité d’armatures transversales pilote d’une manière significative le comportement de ces poutres. Le travail présenté dans cet article propose un modèle poutre multifibre enrichi pour la prise en compte de l’effet de confinement du béton par les armatures transversales. Des déplacements transversaux additionnels d’enrichissement permettent d’enrichir la cinématique de la section transversale pour y calculer l’équilibre. Le modèle est dans un premier temps validé avec des tests simples et une loi de comportement élastique linéaire pour le matériau composant la section., Academic Journal of Civil Engineering, Vol 35 No 1 (2017): Special Issue - RUGC 2017 Nantes

Published
2018

36. Behaviour of a 2D reinforced concrete frame structure under differential seismic excitation

Author

Ghannoum, Maria, Imtiaz, Afifa, Grange, Stéphane, Causse, Matthieu, Cornou, Cécile, Baroth, Julien, Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), ANR-11-EQPX-0040/11-EQPX-0040,RESIF-CORE,Réseau sismologique et géodésique français : l’équipement fondamental(2011), European Project: 262330,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2010-1,NERA(2010), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and ANR-11-EQPX-0040,RESIF-CORE,Réseau sismologique et géodésique français : l'équipement fondamental(2011)

Subjects
Differential Seismic Excitation, Finite Element Model, Nonlinear Behavior, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, Reinforced Concrete Frame Structure, Physics::Geophysics
Abstract

International audience; Two very dense seismographic arrays were deployed in a seismically active area in Greece to incorporate the difference in amplitude and phase between two stations located within the dimension of a structure. The spatial variability in seismic ground motion is generally attributed to the wave passage effect, the incoherence effect, and the local site effect. It can cause severe damage on lifeline structures. This article studies the behavior of a reinforced concrete 2D frame structure subjected to differential seismic excitation at the supports. Both linear and nonlinear finite multifiber element models of the seismic behavior of this structure are used. The nonlinear behavior of the structure, under these different cases, displays different damage patterns and maximum displacements. This study allows evaluating the uncertainty that can be propagated through the finite element model, aiming at reducing variability for structural design purposes.

Published
2018

37. Analyse de fiabilité de la stabilité au glissement des barrages en remblai en utilisant l'expansion de chaos polynomiaux creux

Author

Pierre Breul, Daniel Dias, Xiangfeng Guo, Claudio Carvajal, Laurent Peyras, Polymer-Institut, University of Karlsruhe, University of Karlsruhe (TH), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), GéoMécanique, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Université Blaise Pascal - Clermont-Ferrand 2 (UBP), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Sibille, Luc, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Aix Marseille Université (AMU), UNIVERSITE BLAISE PASCAL CLERMONT FERRAND FRA, Partenaires IRSTEA, and Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)

Subjects
IN-SITU MEASUREMENTS, 0211 other engineering and technologies, 020101 civil engineering, 02 engineering and technology, LIMIT EQUILIBRIUM METHOD, 0201 civil engineering, SPARCE POLYNOMIAL CHAOS EXPANSION, [SPI.GCIV.GEOTECH] Engineering Sciences [physics]/Civil Engineering/Géotechnique, Cohesion (geology), RELIABILITY ANALYSIS, Applied mathematics, Probabilistic analysis of algorithms, SENSITIVITY ANALYSIS, EMBANKMENT DAMS, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, Civil and Structural Engineering, Mathematics, Safety factor, Seismic loading, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, Probabilistic logic, Finite difference method, 6. Clean water, [SDE]Environmental Sciences, Embankment dam, Random variable
Abstract

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE [ADD1_IRSTEA]Hydrosystèmes et risques naturels; International audience; A probabilistic stability analysis of an embankment dam using in-situ measurements is presented in the paper. Three soil properties, including the dry density (), the effective cohesion () and the friction angle () are simulated by means of random variables based on in-situ measurements or laboratory test results, to consider the soil variability. Concerning the deterministic calculations, two models are developed in the study. The first one is a numerical model based on the finite difference method, and the second one is an analytical model based on the limit equilibrium method. For the latter, a two-step Genetic Algorithm (GA) is proposed to locate the best noncircular critical slip surface. These two models are both used for the safety factor evaluation of the studied dam and compared in a probabilistic framework in terms of safety factor distribution and failure probability. The employed reliability method for the probabilistic analysis is the Sparse Polynomial Chaos Expansion (SPCE). The failure probability and the safety factor distribution of the considered dam under normal exploitation conditions and seismic loading conditions are presented. The influence of the random variable distribution type on the probabilistic results is studied. In addition, a PCE-based Global Sensitivity Analysis (GSA) is embedded in order to investigate the contribution of each variable to the safety factor variance.

Published
2018

38. Inner Resonance in Media Governed byHyperbolic and Parabolic Dynamic Equations.Principle and Examples

Author

Guy Bonnet, Claude Boutin, Jean-Louis Auriault, ENTPE, DGCB, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Mécanique et Couplages Multiphysiques des Milieux Hétérogènes (CoMHet), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire de Modélisation et Simulation Multi Echelle (MSME), Université Paris-Est Marne-la-Vallée (UPEM)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), In book edited by : Holm Altenbach, Joël Pouget, Martine Rousseau, Bernard Collet, Thomas Michelitsch, Département génie civil et batiment (DGCB), ENTP, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Mécanique et Couplages Multiphysiques des Milieux Hétérogènes (CoMHet ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Holm Altenbach, and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Paris-Est Marne-la-Vallée (UPEM)

Subjects
Physics, Momentum transfer, effective behaviour, homogenization, Composite media, 02 engineering and technology, [SPI.MECA.SOLID]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Solid mechanics [physics.class-ph], 021001 nanoscience & nanotechnology, 01 natural sciences, Homogenization (chemistry), Classical mechanics, Mass transfer, 0103 physical sciences, Dissipative system, Modeling and design, 0210 nano-technology, 010301 acoustics, Dynamic equation, inner resonance, [SPI.MECA.SOLID]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of the solides [physics.class-ph], Asymptotic homogenization
Abstract

International audience; This chapter deals with the modeling and design of inner resonance media, i.e. media that present a local resonance which has an impact on the overall dynamic behaviour. The aim of this chapter is to provide a synthetic picture of the inner resonance phenomena by means of the asymptotic homogenization method (Sanchez-Palencia, 1980). The analysis is based on the comparative study of a few canonical realistic composite media. This approach discloses the common principle and the specific features of different inner resonance situations and points out theirconsequences on the effective behavior. Some general design rules enabling to reach such a specific dynamic regime with a desired effect are also highlighted. The paper successively addresses different materials having different behaviours and inner structures as elastic composites, reticulated media, permeable rigid and elastic media, undergoing phenomena governed either by momentum transfer or/and mass transfer, in which the inner resonance mechanisms can be highly or weakly dissipative, in situation of inner resonance or inner anti-resonance.

Published
2018

39. A comparison of displacement-based Timoshenko multi-fiber beams finite element formulations and elasto-plastic applications

Author

Stéphane Grange, Panagiotis Kotronis, Nathan Benkemoun, Ibrahim Bitar, Institut de Recherche en Génie Civil et Mécanique (GeM), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Timoshenko beam theory, Engineering, Environmental Engineering, Timoshenko, Fiber (mathematics), business.industry, Elasto plastic, Stiffness, 020101 civil engineering, 02 engineering and technology, Structural engineering, Displacement based, Displacement (vector), Finite element method, 0201 civil engineering, [SPI.MAT]Engineering Sciences [physics]/Materials, 020303 mechanical engineering & transports, 0203 mechanical engineering, shape functions, medicine, displacement-based beam, multi-fiber, medicine.symptom, business, Civil and Structural Engineering
Abstract

International audience; Various formulations of displacement-based Timoshenko multi-fiber beams are compared in this article. After a short literature review, the presentation of the shape functions leading to the stiffness matrices and the consistent nodal forces relative to each formulation are presented and their performances are studied using elastic or elastic perfectly plastic constitutive laws and simple to complex static loadings. The advantages and disadvantages of each formulation are highlighted and general conclusions are drawn on the use of displacement-based Timoshenko multi-fiber beams in engineering. An innovative solution is finally proposed to improve the performance for the case of axial-bending interactions.

Published
2018

40. Revisiting the existence of an effective stress for wet granular soils with micromechanics

Author

Duriez, Jerome, Wan, Richard, Pouragha, Mehdi, Darve, Félix, Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Aix Marseille Université (AMU), Department of Civil Engineering [Calgary], University of Calgary, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), GéoMécanique, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
[SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, [SPI.GCIV.CH]Engineering Sciences [physics]/Civil Engineering/Construction hydraulique
Abstract

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE [ADD1_IRSTEA]Hydrosystèmes et risques naturels; International audience; A possible effective stress variable for wet granular materials is numerically investigated based on an adapted Discrete Element Method (DEM) model for an ideal three-phase system. The DEM simulations consider granular materials made of nearly monodisperse spherical particles, in the pendular regime with the pore fluid mixture consisting of distinct water menisci bridging particle pairs. The contact force-related stress contribution to the total stresses is isolated and tested as the effective stress candidate for dense or loose systems. It is first recalled that this contact stress tensor is indeed an adequate effective stress that describes stress limit states of wet samples with the same Mohr-Coulomb criterion associated with their dry counterparts. As for constitutive relationships, it is demonstrated that the contact stress tensor used in conjunction with dry constitutive relations does describe the strains of wet samples during an initial strain regime, but not beyond. Outside this so-called quasi-static strain regime, whose extent is much greater for dense than loose materials, dramatic changes in the contact network prevent macro-scale contact stress-strain relationships to apply in the same manner to dry and unsaturated conditions. The presented numerical results also reveal unexpected constitutive bifurcations for the loose material, related to stick-slip macro-behavior.

Published
2018

41. A discrete numerical model involving partial fluid-solid coupling to describe suffusion effects in soils

Author

Bruno Chareyre, Nadia Benahmed, R. Aboul Hosn, Luc Sibille, Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Aix Marseille Université (AMU), GéoMécanique, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
Materials science, Soil test, Shear force, FINITE VOLUME, 0211 other engineering and technologies, 02 engineering and technology, CONSTITUTIVE BEHAVIOR, PORE, Matrix (geology), 0203 mechanical engineering, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, Coupling (piping), Internal erosion, Extraction (military), SUFFUSION, Pore finite volume, 021101 geological & geomatics engineering, DISCRETE NUMERICAL MODEL, Finite volume method, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, Mechanics, 15. Life on land, Geotechnical Engineering and Engineering Geology, [SPI.GCIV.CH]Engineering Sciences [physics]/Civil Engineering/Construction hydraulique, Computer Science Applications, 020303 mechanical engineering & transports, [SDE]Environmental Sciences, Erosion
Abstract

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE [ADD1_IRSTEA]Hydrosystèmes et risques naturels; International audience; Suffusion, a particular case of internal erosion in soils, is a particle-scale mechanism involving the selective erosion of fine particles within the matrix of coarse particles under the effect of water seepage. Modifications in the micro-structure as a consequence of the loss of a fine fraction may affect both the hydraulic and the mechanical properties of the soil. Thus leading, in some cases, to drastic consequences. In this study, a discrete numerical model methodology is introduced to investigate the initiation and development of suffusion as well as to analyse its effects on the soil mechanical properties. For that purpose, an original numerical extraction procedure was developed allowing us to mimic the suffusion process by taking into account both the micro-structure of the granular packing and the hydraulic loading in the suffusion development. Such a procedure is based on a one-way fluid-solid coupling where the interstitial flow is solved with a finite volume approach defined at the pore scale. Numerical soil samples subjected to different hydraulic gradients show that depending on the amount and the role of eroded particles in the granular assembly, the eroded medium either shows negligible deformations during erosion but then collapses suddenly once sheared or it deforms significantly during erosion and recovers part of its strength once subjected to shear forces. A non-linear non-monotonic relation between the eroded mass and the mechanical properties of the soil was found.

Published
2018

42. Microstructure-based analysis of cone penetration tests in snow

Author

Peinke, Isabel, Hagenmuller, Pascal, Andò, Edward, Flin, Frédéric, Chambon, Guillaume, Roulle, Jacques, Centre d'Etudes de la Neige (CEN), Centre national de recherches météorologiques (CNRM), Météo France-Centre National de la Recherche Scientifique (CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), GéoMécanique, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology
Abstract

International audience; Cone penetration tests (CPT) are common to measure vertical profiles of the snow hard-ness. The SnowMicroPenetrometer (SMP) is a high-resolution CPT, which allows to link the measuredpenetration strength, especially its high-frequency fluctuations, to microstructural snow characteristics.With a non-homogeneous Poisson point process (NHPP) we are able to get estimations of the number ofbonds, breaking due to the cone indentation and estimations of the strength of the bonds. We did combinedmeasurements of SMP and tomography. Therefore, several samples, spanning different snow types wereimaged twice, once before and once after a CPT. With a new algorithm, we are able to recover and quantifythe displacements between the pre-CPT and post-CPT images. The resulting 3D displacement field will giveus information about the bonds which break and what happens around the SMP tip. With the calculationof the radial displacement, we are able to estimate the size of the compaction zone and the number of thedisplaced grains. We can compare this number to the number of broken bonds, estimated by the NHPP model.

Published
2018

43. Quantification of the amplitude variability of the ground motion in Argostoli, Greece. Variability of linear and non-linear structural response of a single degree of freedom system

Author

Frédéric Dufour, Stéphane Grange, Cécile Cornou, Eleni Koufoudi, Afifa Imtiaz, Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Mécanique des Matériaux et des Structures (M2S), Géomécanique, Matériaux et Structures (GEOMAS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), European Project: 262330,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2010-1,NERA(2010), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )

Subjects
0211 other engineering and technologies, Phase (waves), SDOF, 02 engineering and technology, 010502 geochemistry & geophysics, 01 natural sciences, Displacement (vector), Physics::Geophysics, [SPI]Engineering Sciences [physics], Argostoli, Linear response, 0105 earth and related environmental sciences, Civil and Structural Engineering, 021110 strategic, defence & security studies, Hydrogeology, Building and Construction, Non-linear response, Geotechnical Engineering and Engineering Geology, Geodesy, Term (time), Nonlinear system, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Geophysics, Amplitude, Surface wave, Dense array, Spatial variability, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, Spatial variability of ground motions, Geology
Abstract

International audience; The term “spatial variability of seismic ground motions” denotes the differences in the amplitude and phase content of seismic motions. The effect of such spatial variability on the structural response is still an open issue. In-situ experiments may be helpful in order to answer the questions regarding both the quantification of the spatial variability of the ground motion within the dimensions of a structure as well as the effect on its dynamic response. The goal of the present study is to quantify the variability of the seismic ground motion accelerations in the shallow sedimentary basin of Argostoli, Greece, and thereafter to identify its effect on the linear and non-linear elasto-plastic response of a single degree of freedom system in terms of spectral displacements. Around 400 earthquakes are used, recorded by the 21-element very dense seismological array deployed in Argostoli with inter-station spacing ranging from 5 to 160 meters. The seismic motion variability, evaluated in terms of spectral accelerations, is found to be significant and to increase with inter-station distance and frequency. Thereafter, the amplitude variability in terms of spectral displacements, which is indeed the linear response of a single degree of freedom (SDOF) system with various fundamental periods, is compared with the amplitude variability of a SDOF with non-linear elasto-plastic response. The variability of the maximum top displacement of the linear single degree of freedom system is estimated to be on average 12% with larger variabilities to be observed within two narrow frequency ranges (between 1.5 and 1.7 Hz and between 3 and 4 Hz). Such high variabilities are caused by locally edge-generated diffracted surface waves. The non-linear perfectly elasto-platic structural response of the SDOF system shows that although the variability has the same trends as in the case of linear response, it is almost constantly increased by 5%.

Published
2018

44. Soil reinforcement with geosynthetic for localized subsidence problems : experimental and analytical analysis

Author

Marwan Al Heib, Mouhamad Hassoun, Pascal Villard, Fabrice Emeriault, Institut National de l'Environnement Industriel et des Risques (INERIS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), GéoMécanique, and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
021110 strategic, defence & security studies, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, 0211 other engineering and technologies, Soil Science, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Subsidence, Soil classification, 02 engineering and technology, Soil surface, Lateral earth pressure, Soil reinforcement, Transfer mechanism, Geotechnical engineering, Reinforcement, Terzaghi's principle, Geology, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering
Abstract

This study focuses on the evaluation of the load transfer mechanism and the determination of the shape of the load distribution transmitted to the geosynthetic layer when a cavity appears under granular and cohesive backfills. Trapdoor experimental technique with high-speed acquisition of digital images and continuous monitoring of load and displacements were used for this purpose. Testing different soil types, it has been demonstrated that an approximate parabolic or inverted triangular load distribution seems acceptable for granular soil layer, whereas for cohesive backfill the load distribution could be approximately represented by two concentrated forces near the edges of the cavity. In both cases, an important overload on the soil surface could change the shape of the load acting on the geosynthetic sheet. Experimental results are then approached by Terzaghi’s formulation with an appropriate shape of load distribution and a convenient value of the earth pressure coefficient. Finally, recommendations are proposed to promote a better design of such reinforcement structures.

Published
2018

45. COST TU1404 benchmark on macroscopic modelling of concrete and concrete structures at early age: proof-of-concept stage

Author

Peter Joachim Heinrich, Elisabeth Stierschneider, Miguel Azenha, Giuseppe Sciumè, Stefano Dal Pont, Farid Benboudjema, José Luís Duarte Granja, Karolina Hájková, Vít Šmilauer, Emanuel Strieder, Agnieszka Jędrzejewska, Laurie Lacarrière, Vyacheslav Troyan, Dirk Schlicke, Arnaud Delaplace, Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Matériaux et Durabilité des constructions (LMDC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, University of Minho, Department of Civil Engineering, GéoMécanique, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Lafarge Centre de Recherche [Lyon] (Lafarge LCR Lyon), Lafarge, University of Minho, Departement of civil Engineering, Czech Technical University in Prague (CTU), École normale supérieure - Cachan (ENS Cachan)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), University of Minho [Braga], Lafarge France [Groupe Holcim], Laboratoire de Mécanique et Technologie ( LMT ), École normale supérieure - Cachan ( ENS Cachan ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Matériaux et Durabilité des constructions [Toulouse] ( LMDC ), Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Université Toulouse III - Paul Sabatier ( UPS ), Laboratoire sols, solides, structures - risques [Grenoble] ( 3S-R ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut polytechnique de Grenoble - Grenoble Institute of Technology ( Grenoble INP ) -Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), Czech Technical University in Prague ( CTU ), and Universidade do Minho

Subjects
Numerical Modelling, Structural level, Computer science, Benchmark program, Macroscopic modelling, 0211 other engineering and technologies, Cement, Hydration, 020101 civil engineering, 02 engineering and technology, 0201 civil engineering, 021105 building & construction, medicine, [ SPI ] Engineering Sciences [physics], [ SPI.GCIV ] Engineering Sciences [physics]/Civil Engineering, General Materials Science, Adiabatic process, ComputingMilieux_MISCELLANEOUS, Civil and Structural Engineering, Shrinkage, Science & Technology, business.industry, Stiffness, Building and Construction, Structural engineering, Mechanical behaviour, Creep, Proof of concept, Numerical modelling, Early-age concrete, Benchmark (computing), Stage (hydrology), medicine.symptom, Early age, business, [SPI.GCIV.EC]Engineering Sciences [physics]/Civil Engineering/Eco-conception
Abstract

Modelling of early-age behaviour of cement-based materials is still a challenging task. The challenge is implied by the extent of the knowledge on the subject which results in a variety of different models used for simulation of cement-based materials. That is why a numerical benchmark program has been launched within the COST Action TU1404 aiming at improvement and harmonisation of computational prediction of early-age behaviour of cement-based materials as well as its behaviour on structural level. This paper presents the result of the proof-of-concept stage of the benchmark. The goal of this stage of benchmark was to compare the performance of currently used models for simulation of early-age behaviour of concrete. The participants were requested to simulate thermo-chemomechanical behaviour of simple concrete elements covering adiabatic and real evolution of temperature, shrinkage, stiffness and stresses accounting for early-age creep. The tasks were formulated based on the experimental measurements. This stage of benchmark allowed to evaluate the influence of different phenomena occurring in early-age concrete on the behaviour of early-age concrete structures, define the discrepancies between experimental results and numerical simulations, as well as to indicate the weak points in the models., COST Action TU1404, Competitivity Factors Operational Programme– COMPETE, Polish Ministry of Science and Higher Education (BK-237/RB-6/2018)., info:eu-repo/semantics/publishedVersion

Published
2018

46. Numerical analysis on seismic resistance of a two-story timber-framed structure with stone and earth infill

Author

Stéphane Grange, Laurent Daudeville, Philippe Garnier, E. Fritsch, H. Algusab, Yannick Sieffert, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Technische Universität Dresden (TUD), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Architecture, Environnement & Cultures constructives (AE&CC), École nationale supérieure d'architecture de Grenoble (ENSAG)-Ministère de la Culture et de la Communication (MCC), CRAterre (CRAterre), ANR-10-HAIT-0003,REparH(2010), ANR-15-IDEX-02,CYBER@ALPS,Grenoble Alpes Cybersecurity Institute(2017), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Architecture, Environnement & Cultures Constructives (AE&CC), and ANR-15-IDEX-0002,UGA,IDEX UGA(2015)

Subjects
Visual Arts and Performing Arts, 0211 other engineering and technologies, 020101 civil engineering, 02 engineering and technology, Conservation, seismic resistance, 0201 civil engineering, 021105 building & construction, Architecture, traditional house, Infill, Geotechnical engineering, Seismic resistance, hysteresis behavior, [SPI.GCIV.CD]Engineering Sciences [physics]/Civil Engineering/Construction durable, business.industry, Numerical analysis, multi-stories timber-framed, numercial analysis, Masonry, earth mortar, Haiti, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, nonlinear elements, business, Geology
Abstract

International audience; Due to their seismic resistance, traditional timber-framed structures with masonry infill suffered little damage during recent earthquakes. Moreover, timber-framed structures can be built with reduced costs thanks to the use of locally available materials such as wood, stone, and earth. Based on an experimentally validated numerical simulation for a one-story house, the seismic resistance of a similar two-story house is investigated. A simplified Finite Element Model with linear and nonlinear truss elements is proposed to analyze the seismic resistance of a two-story building. Nonlinear hysteresis constitutive laws are defined only for two majorcomponents of the structure which are assumed to be representative of the global structure behavior: diagonal X-crosses (concentrating the interaction with the infill material) and steel strip connections. These kinds of structures have been overlooked due to a lack of knowledge of their potential behavior in seismic prone area and a lack of building codes and standards for their own design. To promote them, a failure criterion, that might easily be used in engineering studies, is required. This article proposes a simple criterion based on Eurocode 8 to quantify the seismic resistance of one- and two-story houses. The simulation shows that, even in case of high intensity ground motion, the two-story building should not be collapsed. This study may help at designing two-story timber-framed structures in seismic prone areas for (re)construction projects.

Published
2018

47. Reinforced concrete structures at early age: experiment on massive structures and simplified modelling

Author

Mazars, Jacky, GRANGE, Stephane, Briffaut, Matthieu, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Mazars, Jacky

Subjects
[SPI]Engineering Sciences [physics], [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, [SPI] Engineering Sciences [physics], [SPI.GCIV.STRUCT] Engineering Sciences [physics]/Civil Engineering/Structures, [SPI.GCIV] Engineering Sciences [physics]/Civil Engineering, [SPI.GCIV.GCN] Engineering Sciences [physics]/Civil Engineering/Génie civil nucléaire, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, [SPI.GCIV.GCN]Engineering Sciences [physics]/Civil Engineering/Génie civil nucléaire, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

48. Safety of existing arch-dams [La sûreté des barrages-Voûtes existants]

Author

Agresti, P., Roy, M., Andrian, F., Bourdarot, E., Carrere, A., Carvajal, C., Castanier, G., Couturier, B., Emeriault, F., Fabre, J.-P., Fournie, Y., Hoonakker, M., Jellouli, M., Molin, X., Noret, C., Ousset, I., Prévôt, G., Robbe, E., Tardieu, B., Yziquel, A., Artelia Eau & Environnement [Echirolles], Artelia Eau & Environnement [Lyon], EDF (EDF), Coyne et Bellier, Tractebel engineering, Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Comité Technique Permanent des Barrages et Ouvrages Hydrauliques (CTPBOH), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), GéoMécanique, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Société Hydro-Electrique du Midi, Ministère de la Transition Ecologique et Solidaire (MTES), Bureau d'Etude Technique et de Contrôle des Grands Barrages (BETCGB), Ministère de l'Ecologie, de l'Energie du Développement Durable et de la Mer, ISL ingénieries, Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Emeriault, Fabrice

Subjects
Monitoring, Numerical models, Risk analysis, Performance, Regulatory requirements, Arch dams, Performance criterion, Behavior analysis, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Lanthanum, Accidents, Concretes, Structural design, [SPI.GCIV] Engineering Sciences [physics]/Civil Engineering, Abutments (bridge), Behaviour, Arches, Reservoirs (water), Global mechanisms, Innovative practices, Foundations, Risk assessment, Engineering consulting
Abstract

cited By 0; Conference of 26th International Congress on Large Dams, 2018 ; Conference Date: 4 July 2018 Through 6 July 2018; Conference Code:220729; International audience; There are about a hundred arch dams in France, essentially built between 1935 and 1980. These elegant, often majestic, structures testify to the knowledge of a generation of brilliant engineers. These engineers dared to draw pure and thin lines by optimizing the material placement to reconcile the structures safety with the projects costs. The mechanical operating mode ideally depends on the transmission of the efforts to their foundation by mobilizing arch effects. So it seems safe provided that the rock supports resist. In practice the behavior of these structures is complex, especially for geometries which are far from the standard design: arch dams settled in wide or expanded flat-bottom valleys, unfavorable slopes of banks. Due to the number of projects becoming scarce (set apart in some countries), it is essential to assess the safety of existing dams taking into account incidents and accidents analysis of these structures, as well as experiences gained through their behavior analysis carried out for more than 50 years. These experimental lessons allow identifying the main failure modes, by distinguishing what come from a normal adaptation of the structure, from located cracks due to structure hyperstatic design, or from more global mechanisms. The present development of risk analyses and the regulatory requirements to take into account low frequency events require the search for analysis methods and if necessary for solutions (monitoring, remedial works) adapted to possible failure kinematics. In this context, a working group of the French Committee of Dams and Reservoirs, consisting of experts coming from consulting firms, operational groups and monitoring department, has introduced an approach centered on the analysis of the existing arch dams portfolio. This article presents the first results in terms of recommendations of behavior analyses, failure modes, performance criteria and adapted monitoring. In addition, Coyne and Bellier / Tractebel and Artelia, two French engineering consulting firms present their innovative practices on two specific topics, respectively: - concrete abutments behavior and modeling through three examples; - dam modeling taking into account the loading history on structures by “cyclic calculations”. The full text of this article is available in English: http://barrages-cfbg.eu/IMG/pdf/gtvoute_vienne2018.pdf. © 2018 ICOLD/CIGB, Paris, France.

Published
2018

49. The Greenland and Antarctic ice sheets under 1.5 °C global warming

Author

Gaël Durand, Michiel R. van den Broeke, Nicholas R. Golledge, Xavier Fettweis, Xylar Asay-Davis, Heiko Goelzer, Frank Pattyn, Lionel Favier, Luke D. Trusel, Alexander Robinson, Catherine Ritz, Peter Kuipers Munneke, Antony J. Payne, Jan T. M. Lenaerts, Helene Seroussi, Edward Hanna, Rob DeConto, Sophie Nowicki, Laboratoire de Glaciologie [Bruxelles], Université libre de Bruxelles (ULB), Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Department of Geography [Sheffield], University of Sheffield [Sheffield], Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Département de Géographie, Université de Liège, Institute for Marine and Atmospheric Research [Utrecht] (IMAU), Utrecht University [Utrecht], Laboratoire de mécanique des sols, structures et matériaux (MSSMat), CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Université Libre de Bruxelles [Bruxelles] (ULB), EDGe, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec, Sub Dynamics Meteorology, and Marine and Atmospheric Research

Subjects
010504 meteorology & atmospheric sciences, Drainage basin, Forcing (mathematics), Environmental Science (miscellaneous), 010502 geochemistry & geophysics, 01 natural sciences, F860 Climatology, medicine, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, ComputingMilieux_MISCELLANEOUS, Collapse (medical), 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Global warming, Lead (sea ice), Glaciologie, [SDU]Sciences of the Universe [physics], 13. Climate action, Climatology, Ice sheet, medicine.symptom, Surface mass, Geology, Social Sciences (miscellaneous)
Abstract

Even if anthropogenic warming were constrained to less than 2 °C above pre-industrial, the Greenland and Antarctic ice sheets will continue to lose mass this century, with rates similar to those observed over the past decade. However, nonlinear responses cannot be excluded, which may lead to larger rates of mass loss. Furthermore, large uncertainties in future projections still remain, pertaining to knowledge gaps in atmospheric (Greenland) and oceanic (Antarctica) forcing. On millennial timescales, both ice sheets have tipping points at or slightly above the 1.5–2.0 °C threshold; for Greenland, this may lead to irreversible mass loss due to the surface mass balance–elevation feedback, whereas for Antarctica, this could result in a collapse of major drainage basins due to ice-shelf weakening., SCOPUS: re.j, info:eu-repo/semantics/published

Published
2018

50. Suffusion and its effects on the mechanical behavior of granular soils : numerical and experimental investigations

Author

Aboul Hosn, Rodaina, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), GéoMécanique, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Grenoble Alpes, Luc Sibille, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and STAR, ABES

Subjects
Mechanical characterization, [SPI.MECA.MEMA] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], Internal erosion, Caractérisation mécanique, Essais de suffusion, [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], Modèle numérique discret, Discrete numerical model, Fluid-Solid coupling, Érosion interne, Granular soil, Couplage fluide-Solide, Sol granulaire, Suffusion tests
Abstract

Suffusion is a particular case of internal erosion taking place in hydraulic earth structures. It is characterized by the detachment and migration of fine particles by interstitial flow leaving behind the granular skeleton. Such modifications in the soil microstructure may lead to deformations at the macroscopic scale and may influence the mechanical behavior of the soil. This research was devoted to investigate the suffusion mechanism and its impact on the mechanical properties of cohesionless soils. To achieve this objective, two approaches were followed in this work: numerical and experimental approaches. A discrete numerical model was defined to describe quantitatively the soil macroscopic behavior and to analyze the microstructure of granular assemblies. It is based on the use of spherical particles and contact rolling resistance, as well as a new method of compaction to mimic the one used in laboratory and to reach a wide range of initial densities. The model was validated through comparison of numerical results with experimental data. This model was first applied on granular assemblies with different fines contents to study the role of fine particles with respect to a given soil microstructure, without taking into account an erosion process. It was shown that there exists a fines content, below the threshold, where fine particles may start to participate in the force transfer that if suffusion initiates and mobilizes these particles, it may affect the macroscopic behavior of the soil. Thereafter, a simplified kinetics of grain extraction was proposed to describe the suffusion process. It was based on a one-way fluid-solid coupling approach. The importance of this extraction procedure is that, on one hand, it takes into account complex geometric and hydraulic criteria; on the other hand, the model involves an affordable computational cost. This procedure was validated based on experimental tests carried out using a newly developed suffusion apparatus. Consequences of this erosion on the mechanical properties of soils were characterized from experimental and simulated triaxial compression tests. Suffusion development and its consequences on the macroscopic behavior are discussed from the results obtained in terms of the initial soil density and gradation, the hydraulic loading and the type of eroded particles (active or inactive in the force transfer)., La suffusion est un cas particulier d'érosion interne qui apparait dans les ouvrages hydrauliques. Elle se caractérise par le détachement et le transport des particules fines à travers les gros grains sous l'action d'un écoulement hydraulique en laissant derrière un squelette granulaire dont les caractéristiques en termes de densité et d'arrangement géométrique granulaire ont été changées. De telles modifications dans la micro-structure du sol peuvent conduire à des déformations à l'échelle macroscopique et peuvent influencer le comportement mécanique du sol. Ce travail a été consacré à l'étude du mécanisme de suffusion et à son impact sur les propriétés mécaniques des sols non-cohésifs. Pour atteindre cet objectif, deux approches ont été suivies dans ce travail: l'une numérique et l'autre expérimentale. Un modèle numérique discret a été défini pour décrire quantitativement le comportement macroscopique du sol et analyser la micro-structure des assemblages granulaires. Il est basé sur l'utilisation de particules sphériques et la résistance au roulement aux contacts, ainsi que sur une nouvelle méthode de compactage des échantillons pour simuler celle utilisée au laboratoire, et atteindre une large gamme de densités initiales. Le modèle a été validé par comparaison de résultats numériques et de données expérimentales. Ce modèle a d'abord été appliqué sur des assemblages granulaires avec des teneur en fines différentes afin d'étudier le rôle des particules fines pour une micro-structure de sol donnée, sans tenir compte d'un processus d'érosion. Il a été montré qu'il existe un pourcentage de fines, en dessous de la teneur seuil, où des particules fines peuvent commencer à participer au transfert de force, et que, si la suffusion s'initie et mobilise ces particules, ceci pourra affecter le comportement macroscopique du sol. Par la suite, une cinétique simplifiée d'extraction du grain a été proposée pour décrire le processus de suffusion. Elle est basée sur une approche de couplage fluide-solide partielle. L'intérêt de cette procédure d'extraction est que, d'une part, elle tient en compte des critères géométriques et hydrauliques complexes; d'autre part, le modèle induit un coût de calcul raisonnable. Cette procédure a été validée sur la base d'essais expérimentaux de suffusion effectués avec un dispositif nouvellement développé. Les conséquences de cette érosion sur les propriétés mécaniques des sols ont été caractérisées par la réalisation en laboratoire et la simulation d'essais de compression triaxiale. Le développement de la suffusion et ses conséquences sur le comportement macroscopique sont discutés en terme de densité et granulométrie initiale du sol, de chargement hydraulique et du type de particules érodées (actives ou inactive vis-à-vis du transfert de force).

Published
2017

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