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This study emphasizes the importance of accurate calibration in sediment transport models and highlights the transformative role of artificial intelligence (AI), specifically machine learning, in improving accuracy and computational efficiency. Extensive experiments were carried out in the Riba-Roja reservoir, which is located in the northeastern Iberian Peninsula. The accumulated sediment volume (ASV) curve was used to calibrate these experiments. The optimal ASV curve was found to be very close to the experimental data, with only minor differences in upstream areas. The results revealed a consistent rate of sediment transport and settling. Furthermore, the study investigated the capabilities of deep neural networks (DNNs) in predicting ASV curves and observing variable performance. In essence, the study highlights AI's potential for enhancing sediment transport models., Postprint (published version)

In many applications, free surface flow through rigid porous media has to be modeled. Examples refer to coastal engineering applications as well as geotechnical or biomedical applications. Albeit the frequent applications, slight inconsistencies in the formulation of the governing equations can be found in the literature. The main goal of this paper is to identify these differences and provide a quantitative assessment of different approaches. Following a review of the different formulations, simulation results obtained from three alternative formulations are compared with experimental and numerical data. Results obtained by 2D and 3D test cases indicate that the predictive differences returned by the different formulations remain small for most applications, in particular for small porous Reynolds number ReP < 5000. Thus it seems justified to select a simplified formulation that supports an efficient algorithm and coding structure in a computational fluid dynamics environment. An estimated accuracy depending on the porous Reynolds number or the mean grain diameter is given for the simplified formulation., Open Access funding enabled and organized by Projekt DEAL., Peer Reviewed, Postprint (published version)

This is the peer reviewed version of the following article: [Zorrilla, R, Larese de Tetto, A, Rossi, R. A discontinuous Nitsche-based finite element formulation for the imposition of the Navier-slip condition over embedded volumeless geometries. Int J Numer Meth Fluids. 2021; 93: 2968– 3003. https://doi.org/10.1002/fld.5018], which has been published in final form at https://doi.org/10.1002/fld.5018. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving, This work describes a novel formulation for the simulation of incompressible Navier–Stokes problems involving nonconforming discretizations of membrane-like bodies. The new proposal relies on the use of a modified finite element space within the elements intersected by the embedded geometry, which is represented by a discontinuous (or element-by-element) level set function. This is combined with a Nitsche-based imposition of the general Navier-slip boundary condition, to be intended as a wall law model. Thanks to the use of an alternative finite element space, the formulation is capable of reproducing exactly discontinuities across the embedded interface, while preserving the structure of the graph of the discrete matrix. The performance, accuracy and convergence of the new proposal is compared with analytical solutions as well as with a body fitted reference technique. Moreover, the proposal is tested against another similar embedded approach. Finally, a realistic application showcasing the possibilities of the method is also presented., European Commission, H2020-FETHPC-2016-2017-800898; International Graduate School of Science and Engineering (IGSSE)), ATMOPACE; Istituto Nazionale di Alta Matematica “Francesco Severi”, Ministero dell'Università e della Ricerca, Programma per Giovani Ricercatori “Rita Levi Mon; Secretaría de Estado de Investigación, Desarrollo e Innovación, CEX2018-000797-S, Peer Reviewed, Postprint (author's final draft)

Bulk handling, transport and processing of granular materials and powders are fundamental operations in a wide range of industrial processes and geophysical phenomena. Particulate materials, which can be found in nature, are usually characterized by grain size which can range across several scales: from nanometre to the order of metre. Depending on the volume fraction and shear strain conditions, granular materials can have different behaviours and often can be expressed as a new state of matter with properties of solids, liquids and gases. For the above reasons both the experimental and the numerical analysis of granular media is still a difficult task and the prediction of their dynamic behaviour still represents nowadays an important challenge. The main goal of the current thesis is the development of a numerical strategy with the objective of studying the macroscopic behaviour of dry granular flows in quasi-static and dense flow regime. The problem is defined in a continuum mechanics framework and the balance laws, which govern the behaviour of a solid body, are solved by using a Lagrangian formalism. The Material Point Method (MPM), a particle-based method, is chosen due to its features which make it very suitable for the solution of large deformation problems involving complex history-dependent constitutive laws. An irreducible formulation using a Mohr-Coulomb constitutive law, which takes into account geometric non-linearities, is implemented within the MPM framework. The numerical strategy is verified and validated against several benchmark tests and experimental results, available in the literature. Further, a mixed formulation is implemented for the solution of granular flows that undergo undrained conditions. Finally, the developed MPM strategy is used and tested against the experimental study performed for the characterization of the flowability of several types of sucrose. The capabilities and limitations of this numerical strategy are observed and disc, El manejo, el transporte y el procesamiento de materiales granulares y polvo son operaciones fundamentales en una amplia gama de procesos industriales y de fenómenos geofísicos. Los materiales particulados, que pueden ser encontrados en la naturaleza, generalmente están caracterizados por el tamaño del grano, que puede variar entre varios órdenes de magnitud: desde el nanómetro hasta el orden de los metros. En función de las condiciones de fracción volumétrica y de deformación de cortante, los materiales granulares pueden tener un comportamiento diferente y a menudo pueden expresarse como un nuevo estado de materia con propiedades de sólidos, de líquidos y de gases. A causa de las observaciones antes mencionadas, tanto el análisis experimental como la simulación numérica de medios granulares es aún una tarea compleja y la predicción de su comportamiento dinámico representa aun hoy día un desafío muy importante. El principal objetivo de esta tesis es el desarrollo de una estrategia numérica con la finalidad de estudiar el comportamiento macroscópico de los flujos de medios granulares secos en régimen cuasiestático y en régimen dinámico. El problema está definido en el contexto de la mecánica de medios continuos y las leyes de equilibrio, que gobiernan el comportamiento del cuerpo sólido, y están resueltas mediante un formalismo Lagrangiano. El Metodo de los Puntos Materiales (MPM), método basado en el concepto de discretización del cuerpo sólido en partículas, está elegido por sus características que lo convierten en una técnica apropiada para resolver problemas de grandes deformaciones donde se tienen que utilizar complejas leyes constitutivas. En el marco del MPM está implementada una formulación irreducible que usa una ley constitutiva de Mohr-Coulomb y que tiene en cuenta no-linealidades geométricas. La estrategia numérica está verificada y validada con respecto a tests de referencia y resultados experimentales disponibles en la literatura. Además, se ha implemen, Postprint (published version)

This work describes a novel formulation for the simulation of Navier–Stokes problems including embedded objects. The new proposal is based on the use of a modified finite element space, which replaces the standard one within the elements intersected by the immersed geometry. The modified space is able to exactly reproduce the jumps happening at the embedded boundary while preserving the conformity across the faces intersected by the embedded object. The paper focuses particularly on the imposition of a slip boundary condition on the surface of the embedded geometry, proposing a new technique for the application of such constraint. The new proposal is carefully benchmarked using the results of a body fitted technique and of an alternative embedded approach. Potential applications of interest are also presented., Peer Reviewed, Postprint (author's final draft)

Within the past two decades, mass movements hazards involving fast and large soil deformation have increased significantly in frequency and magnitude due to their strong relation to climate changes and global warming. These phenomena often bring along rocks, debris, and heavy materials that can extensively damage and destroy the landscape and infrastructures, causing devastating economic loss, and often, human casualties. The risk of future disasters continues to escalate with the increase of real estate development in suburban areas, including mountainous regions. Further assessment and prediction on such disasters and their countermeasures are, therefore, in high economic demands. One of the most intuitive ways is to install protective structures in mountain slopes and valleys that can hold the materials brought by the moving landslides. While the current state of the art of landslide prediction using numerical methods has been mainly dominated by the development of advanced geomechanical models suited for different types of soil materials, e.g. multi-phase unsaturated soil model, this study focuses more on the interaction of such phenomena with the installed protective structures. Here, an implicit formulation of material point method (MPM) is implemented to model the landslides considering finite strain assumption. Furthermore, a staggered coupling scheme with traditional Finite Element Method (FEM) is proposed to simulate accurately and robustly the dynamic force and displacement coupling of soil-structure interaction (SSI). All developments of the method are implemented within the Kratos-Multiphysics framework [1] and available under the BSD license (https://github.com/KratosMultiphysics/Kratos/wiki). In the future works, more adequate consideration of coupling scheme and material models considering damage and fracture will be investigated before conducting a real-scale landslide simulation.

The final publication is available at Springer via http://dx.doi.org/10.1007/s00466-018-1647-9, In this work a stabilized mixed formulation for the solution of non-linear solid mechanics problems in nearly-incompressible conditions is presented. In order to deal with high material deformation, an implicit Material Point Method is chosen. Such choice allows avoiding the classical limitations of the Finite Element Method, e.g., element tangling and extreme mesh distortion. The proposed mixed formulation, with displacement and pressure as primary variables, is tested through classical benchmarks in solid and geo-mechanics where a Neo-Hookean, a J2 and a Mohr-Coulomb plastic law are employed. Further, the stabilized mixed formulation is compared with a displacement-based formulation to demonstrate how the proposed approach gets better results in terms of accuracy, not only when incompressible materials are simulated, but also in the case of compressible ones., Peer Reviewed, Postprint (author's final draft)

This thesis presents and validates the numerical solution strategy developed by CIMNE to solve the multi-phase flow problem associated to oil recovery in experimental laboratory samples. First of all, a review of the most relevant physical concepts associated to oil recovery process, known as Enhanced oil recovery processes (EOR) are presented. Thus, the physical problem and the adopted computational solution are better understood. The developed computational model simulates the laboratory experiments on cylindrical samples using a multiscale approach. The macroscale model analyses the sample at the same laboratory conditions while the mesoscale model analyses the pore scale of the sample. Mesoscale model output provides the relative permeability curves that are transferred to the macroscale model to evaluate the evolution of phase saturations in time and to obtain the residual oil. The goal of this work is to assess the validity of the developed strategy for the mesoscale model by performing a set of sensibility analysis. These analyses study the relative permeabilities curves in order to detect whether the model is giving proper results or not., Esta tesina presenta y valida un método computacional desarrollado en CIMNE para resolver el problema multifásico asociado a la recuperación de petróleo en las probetas experimentales de laboratorio. Primeramente, se hace un breve explicación de los conceptos físicos más relevantes asociados a los procesos de recuperación de petróleo, conocidos como procesos de recuperación de petróleo mejorados. De esta forma, el problema físico y la solución numérica adoptada son mas fácilmente entendibles. El método computacional desarrollado simula los experimentos que se realizan en laboratorio sobre probetas cilíndricas y las analiza utilizando un enfoque multiescala. La macro escala analiza la probeta con las mismas condiciones presentadas en el laboratorio mientras que la micro escala analiza la probeta a escala de poro. Del modelo mesoscopico se obtienen las curvas de permeabilidad relativa, las cuales son transferidas al modelo macroscópico para evaluar la saturación de las fases en el tiempo y obtener el petróleo residual. El objetivo de este trabajo es evaluar la validez del método desarrollado en la mesoescala. Esta validación se lleva a cabo realizando unos análisis de sensibilidad que estudian las curvas de permeabilidad relativa obtenidas y así poder detectar si el modelo genera buenos resultados o no.

This paper presents the application of a stabilized mixed Particle Finite Element Method (PFEM) to the solution of viscoplastic non-Newtonian flows. The application of the proposed model to the deformation of granular non-cohesive material is analysed. A variable yield threshold modified Bingham model is presented, using a Mohr Coulomb resistance criterion. Since the granular material is expected to undergo severe deformation, a Lagrangian approach is preferred to a fixed mesh one. PFEM is the adopted technique. The detail of the discretization procedure is presented and the Algebraic Sub-Grid Scale (ASGS) stabilization technique is introduced to allow for the use of equal order interpolations for velocity and pressure in a consistent way. The matrix form of the problem is given. Finally, the differences between the regularized Bingham and the variable yield models are discussed in some examples., Peer Reviewed, Postprint (published version)

The simulation of large deformation problems, involving complex history-dependent constitutive laws, is of paramount importance in several engineering fields. Particular attention has to be paid to the choice of a suitable numerical technique such that reliable results can be obtained. In this paper, a Material Point Method (MPM) and a Galerkin Meshfree Method (GMM) are presented and verified against classical benchmarks in solid mechanics. The aim is to demonstrate the good behavior of the methods in the simulation of cohesive-frictional materials, both in static and dynamic regimes and in problems dealing with large deformations. The vast majority of MPM techniques in the literature are based on some sort of explicit time integration. The techniques proposed in the current work, on the contrary, are based on implicit approaches, which can also be easily adapted to the simulation of static cases. The two methods are presented so as to highlight the similarities to rather than the differences from, Peer Reviewed, Postprint (published version)

The maturity of numerical techniques both in Computational Structural and Fluid Dynamics, accompanied by the availability of affordable high-performance hardware, allows the use of virtual rapid-prototyping facilities as realistic alternatives to traditional wind tunnel experiments. This work aims to present a virtual wind tunnel tool that combines both “standard” body-fitted approaches and innovative embedded techniques. Two are the distinctive features of the work. Firstly, it allows the simulation of membrane structures subjected to large displacements. This is typically challenging both for embedded solvers, due to the need of modelling a strong discontinuity of the flow field in correspondence of the structural position, and for body-fitted techniques, due to the large displacement regime. Secondly, it allows combining body fitted and embedded structures within the same simulation. All the presented strategies are developed both in Open MP and MPI., Postprint (published version)

Heat treatment processing consists in heating a metallic material above austenitization temperature to later quickly cool it down. The accurate simulation of this phenomenon is a current industrial need in order to predict the outcome of their processes and therefore save time and money avoiding extensive prototyping phases. The aim of this master thesis is to integrate a microstructural model inside the commercial code Stampack, such that it can be used in simulation of hot stamping, in which a blank sheet is quenched and shaped at the same time

This paper presents a finite element solver for the simulation of steady non-Newtonian flow problems, using a regularized Bingham model, with adaptive mesh refinement capabilities. The solver is based on a stabilized formulation derived from the variational multiscale framework. This choice allows the introduction of an a posteriori error indicator based on the small scale part of the solution, which is used to drive a mesh refinement procedure based on element subdivision. This approach applied to the solution of a series of benchmark examples, which allow us to validate the formulation and assess its capabilities to model 2D and 3D non-Newtonian flows., Postprint (author's final draft)

The main objective of this work lies in the development of a variational implicit Material Point Method (MPM), implemented in the open source Kratos Multiphysics framework. The ability of the MPM technique to solve large displacement and large deformation problems is widely recognised and its use ranges over many problems in industrial and civil engineering. In the current work the continuum based implicit MPM is applied to engineering applications, where granular material flow is involved. For the resolution of the length and time scale of these particular problems, both continuum and discrete models are typically used. Even if discrete techniques predict more feasible results, nowadays, their use is limited to the investigation of element tests of particles, or to the simulation of reduced systems, not allowing to make important decisions in the analysis and design of granular processes. Some advantages of MPM over discrete methods are tested, such as, the ability to simulate granular flow at the large scale with acceptable computational cost and the capability to get information of stress and strain state in a more straightforward way. The focus of this paper is a comparative study between an irreducible and a mixed formulation, both implemented in the MPM code, to assess the improvement in accuracy and reliability of the numerical results when the latter formulation is adopted., Postprint (published version)

Nowadays, dam safety is becoming more relevant in our society due to the importance of its functions (power generation, water supply, flood control) and the severity of the consequences in case of a serious breakdown. The "safety of hydraulic infrastructures" is one of the priorities according to the R&D Spanish State Program which is oriented to social challenges. Thanks to recent improvements in the modelling of dams as well as the evolution of computational resources, it is possible to perform more detailed analysis. However, most of commercial software is devoted to more common problems (e.g. buildings, bridges) without considering specific aspects of dams: concrete ageing process, joints during the construction process, contact with the ground or uplift pressure. The development of a specific application for dam engineering, both for construction phase and operating period, is the main objective of this project. The thesis presents the computational tool, which is based on finite element formulations and solves thermomechanical problem using weak coupling, designed for analysing the operating period. The proposed software is validated with a real case: La Baells dam. The computational results have shown excellent agreement with the obtained data during monitoring process.

The development of overtopping protection systems often requires detailed analyses of complex physical phenomena. This hinders the comprehensive knowledge of their behavior, and therefore the development of suitable design criteria. In recent years, the authors have developed and validated different methods, combining continuous, particle and discrete numerical techniques, to obtain accurate and reliable solutions of different numerical problems involving fluid-soil-structure interaction. In this contribution, some applications of these methods to the study of dam protection against overtopping are presented. The main advantages of this approach include the ability to extract results of the governing variables (pressure, velocity) at any location of the domain, and the possibility to consider scenarios without the restrictions of the experimental facilities (flow rates, size, scale effects). In particular, the contribution gathers examples of application of numerical methods in a) analysis of rockfill dam stability against overtopping, including seepage evolution and deformation of the downstream shoulder, and b)stability analysis of wedge-shaped-blocks subjected to vandalism., Postprint (published version)

Implementation of a FSI procedure involving the interaction of shell structures and fluids.

This paper presents the application of a stabilized mixed pressure/velocity finite element formulation to the solution of viscoplastic non-Newtonian flows. Both Bingham and Herschel–Bulkley models are considered. The detail of the discretization procedure is presented and the Orthogonal Subgrid Scale (OSS) stabilization technique is introduced to allow for the use of equal order interpolations in a consistent way. The matrix form of the problem is given. A series of examples is presented to assess the accuracy of the method by comparison with the results obtained by other authors. The extrusion in a Bingham fluid and the movement of a moving and rotating cylinder are analyzed in detail. The evolution of the streamlines, the yielded and unyielded regions, the drag and lift forces are presented. These benchmark examples show the capacity of the mixed OSS formulation to reproduce the behavior of a Bingham and Herschel–Bulkley flows with the required accuracy., Peer Reviewed, Postprint (author's final draft)

Wedge shaped blocks (WSB) are attracting increasing attention as protection against overtopping for earth and rock-fill dams. However, there are limited examples of application and some aspects of the technology merit additional research and improvement. One key issue is the design of drainage and supporting layer for WSB protections. During overtopping, part of the overflow leaks through the joints between blocks, hence circulating through the granular material. The permeability and thickness of the supporting layer must be sufficient to prevent the flow from generating pressure on the bottom side of the blocks, which contributes to its destabilization. However, it must also be structurally stable to avoid undesirable deformations on the downstream face. Both the material permeability and the layer thickness determine the hydraulic behavior of this element. These, together with the weight of the blocks and the slope of the downstream face, directly influence mass and block stability. These aspects should be taken into account for the numerical modeling of seepage through the supporting layer. To this end, an application of the open source software Kratos Multi-physics was employed. A parametric study was conducted to quantify the influence of each design variable in the safety factor against mass sliding of the supporting and drainage layer., Postprint (published version)

Rock ll dams are certainly one of the most important engineering structures due to their economic advantages and exible design. Unfortunately their vulnerability to overtopping still remains their weakest point. For that reason, several research groups are interested in both the numerical and experimental analysis of this phenomenon. In this work we focused on the numerical analysis. The previous work developed in CIMNE on a coupled PFEM-Eulerian free surface Compu- tational Fluid Dynamic (CFD-PFEM) technique for the simulation of porous problems has been studied and extended in the present work. The Particle Finite Element second generation method (PFEM-2) has been used as an alter- native to the Particle Finite Element Method (PFEM). Hence a new coupling strategy, called CFD-PFEM-2, has been developed. On one hand, the uid free surface problem outside and inside the rock ll slope is treated using a unique Eulerian xed mesh formulation. On the other hand, the structural dam response is analyzed using a mixed Eulerian--Lagrangian framework ( the PFEM-2 method). A comparison between the coupled strategies CFD-PFEM, and CFD-PFEM-2 has been performed. Additionally, all the numerical results are compared with experiments on prototype rock ll dams. The results obtained with the new strategy show a good agreement with both the experi- mental results and the CFD-PFEM code. Furthermore, the computational efficiency between the two numerical strategies was found to be almost identical. Given the similar accuracy and required computational power, it is concluded that the CFD-PFEM-2 is a competitive strategy to simulate the phenomenon.

Durante del trabajo final de master se realizará la optimización de la simulación del contacto mecánico dentro de un código de elementos finitos de aplicación industrial. Las tareas incluyen búsqueda bibliográfica y estudio de los algoritmos de contacto clásicos, con especial énfasis en el "Contact Domain Method"; el cual se implementará y validará con casos industriales con el objetivo de conseguir mayor rapidez y robustez en la solución, comparando con el método que actualmente se está empleando en el código

In the last decades, the technology of dam protection has undergone major advancements. The increasing demand for safety in modern society has created the need for cost-effective measures to protect critical infrastructure such as dams. This situation has resulted in the drafting of new regulations and technical manuals in countries like Norway, Sweden, and the USA, among others. Dam Protections against Overtopping and Accidental Leakage includes the latest advances in dam protection, and a portfolio of applications in representative case studies, Peer Reviewed, Postprint (published version)

This paper aims to present and validate a numerical technique for the simulation of the overtopping and onset of failure in rockfill dams due to mass sliding. This goal is achieved by coupling a fluid dynamic model for the simulation of the free surface and through-flow problems, with a numerical technique for the calculation of the rockfill response and deformation. Both the flow within the dam body and in its surroundings are taken into account. An extensive validation of the resulting computational method is performed by solving several failure problems on physical models of rockfill dams for which experimental results have been obtained by the authors., Postprint (published version)

El fenómeno del oleaje causado por deslizamientos de laderas de embalse un escenario formado por dos procesos, uno de tipo geomecánico y otro, hidrodinámico. El primero está relacionado con el origen de la inestabilidad de la ladera y las características del deslizamiento mientras que el segundo se refiere fundamentalmente a la generación del oleaje y su propagación, dependiendo el proceso hidrodinámico del geomecánico así como de las características del embalse. El efecto inmediato de un deslizamiento de ladera sobre una superficie de agua estática es la generación de un tren de olas que se propaga tridimensional o bidimensionalmente de acuerdo a las condiciones del cuerpo que delimita el agua, pudiendo describirse el proceso en cinco etapas:desprendimiento delmaterial de ladera, generación de ola, propagación de ola, interacción con embalse y márgenes y propagación de onda aguas abajo y efecto sobre estructuras (Garrote and Laguna 2007).Para estudiar este fenómeno, se ha realizado unacampaña de ensayos en modelo físico en el Laboratorio de Hidráulica de la ETSIde Caminos, Canales y Puertos de la UPM. Se han utilizado materiales con diferentes grados de fragmentación, variando parámetros como la pendiente del plano de deslizamientoyla altura de agua en elembalse. El principal objetivo de esta campañaconsiste en analizar la influencia del grado de fragmentación del material deslizado sobre las características del oleaje generado., Postprint (published version)

El presente Trabajo de Fin de Máster se enfoca en eval uar, mediante la modelización y simulación numérica, la eficiencia del imbornal modelo Barcelona, es decir, cuánta agua es capaz de captar respecto al caudal de agua que discurre por la calle. Para llevar a cabo todo el proceso, primeramente se ha modeli zado en 3D mediante GID l a plataforma construida en el Laboratorio de Hidráulica de la E.T.S.E.C.C.P.B. en la UPC reproduciendo así el ancho de un vial urbano. Para la simulación se ha utilizado el programa Kratos Multiphysics desa rrollado por el Cimne. En la segunda fase del trabajo y una vez efectuadas las diferentes modelizaciones y simulaciones se han analizado los resultados obtenidos para así poder determinar si el modelo tridimensional utilizado permite una simulación correcta y si ésta es óptima d e realizar de una manera rápida y sencilla, es decir, a nivel de usuario mediante Kratos . Una v ez finalizado el análisis de los resultados se ex traerán una serie de conclusiones de los mismos y se plantearan posibles mejoras para que, en un futuro, el es tudio pueda ser retomado y ampliado con más simulaciones teniendo en cuenta otras tipologías de rejas y aplicando diferentes condiciones geométricas y de contorno. Por último, este TFM también puede llegar a servir como guía de usuario para todo aquel que quiera iniciarse con Kratos Multiphysics en entorno GID, ampliar el presente trabajo o trate de resolver otras tipologías de problemas con este software dentro del ámbito de la ingeniería.

The aim of the present work is to present an overview of some numerical procedures for the simulation of free surface flows within a porous structure. A particular algorithm developed by the authors for solving this type of problems is presented. A modified form of the classical Navier–Stokes equations is proposed, with the principal aim of simulating in a unified way the seepage flow inside rockfill-like porous material and the free surface flow in the clear fluid region. The problem is solved using a semi-explicit stabilized fractional step algorithm where velocity is calculated using a 4th order Runge–Kutta scheme. The numerical formulation is developed in an Eulerian framework using a level set technique to track the evolution of the free surface. An edge-based data structure is employed to allow an easy OpenMP parallelization of the resulting finite element code. The numerical model is validated against laboratory experiments on small scale rockfill dams and is compared with other existing methods for solving similar problems., Peer Reviewed, Postprint (author’s final draft)

Landslide-generated impulse waves may have catastrophic consequences. The physical phenomenon is difficult to model because of the uncertainties in the kinematics of the mobilised material and to the intrinsic complexity of the fluid–soil interaction. The particle finite element method (PFEM) is a numerical scheme that has successfully been applied to fluid–structure interaction problems. It uses a Lagrangian description to model the motion of nodes (particles) in both the fluid and the solid domains (the latter including soil/rock and structures). A mesh connecting the particles (nodes) is re-generated at every time step, where the governing equations are solved. Various constitutive laws are used for the sliding mass, including rigid solid and the Newtonian and non-Newtonian fluids. Several examples of application are presented, corresponding both to experimental tests and to actual full-scale case studies. The results show that the PFEM can be a useful tool for analysing the risks associated with landslide phenomena, providing a good estimate to the potential hazards even for full-scale events., Peer Reviewed, Postprint (author's final draft)

The meshless method Smoothed Particle Hydrodynamics (SPH) is one of the primarily developed numerical methods in the meshless methods family. It has been proven to work well with problems of free surface fluid flows. For the purpose of this thesis, the Smoothed Particle Hydrodynamics method and its current capabilities were studied. Using the obtained knowledge from the literature, a free surface fluid flow application was implemented in the framework of KRATOS multiphysics. Some well known benchmark problems were reproduced using the generated SPH solver. The algorithm's ability to catch the correct free surface evolution and obtain an accurate pressure distribution of free surface problems were analyzed. Furthermore, some programming aspects of coding for meshless methods were discussed from the computational workload point of view. Using the developed application, it was demonstrated that in order to create a generic SPH fluid solver that is able to model any type of fluid, some additional corrections must be applied to the SPH solution. These corrections, although being very convenient to obtain good particle tracking of the fluid motion, affect the pressure distribution of the flow excessively and make the weakly compressible SPH method untrusted for the pressure results of fluid flow problems.

La tecnología de protecciones de presas de materiales sueltos ha experimentado un gran avance en las últimas décadas. El estado del arte de protecciones incluye tipologías muy diferentes en función del origen del daño al que se pretende hacer frente, el grado de protección deseado y de las características específicas de la presa a proteger, entre otras. En este artículo se van a tratar dos tipos de protecciones de carácter muy diferente: las protecciones tipo repié y las protecciones mediante bloques prefabricados en forma de cuña (en adelante, BFC). En el caso de las protecciones tipo repié, aplicables a presas de materiales sueltos con espaldón de aguas abajo de escollera, se realiza una breve descripción del estado del arte de la tecnología y de sus aplicaciones así como de la innovación conseguida en este campo a partir de las investigaciones desarrolladas en la Universidad Politécnica de Madrid (UPM), en colaboración con el Centro de Estudios Hidrográficos del CEDEX y el Centro Internacional de Métodos Numéricos en la Ingeniería (CIMNE), en el marco del proyecto de investigación del Plan Nacional denominado EDAMS, y cuyo resultado directo ha sido la tesis doctoral titulada “Mejora de la seguridad de las presas de escollera frente a percolación accidental mediante protecciones tipo repié”. En la parte dedicada a la protección mediante BFC`s se describe la tecnología, sus posibilidades de utilización dentro de la ingeniería de presas y se presenta el caso de la presa de Barriga (Burgos), como primera aplicación mundial de esta tecnología para el diseño de un aliviadero de servicio sobre el propio cuerpo de una presa de materiales sueltos en explotación., Postprint (published version)