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In the construction industry, increased efforts are being made to automate production processes using industrial robots in order to increase efficiency, improve quality and optimize the use of materials. Tunnel construction is particularly suitable for the use of modern production methods, as the increased use of machines and the high repetition factor of the components used make it possible to scale production technology across project boundaries. This paper provides examples of current developments in segment production, in particular the use of industrial robots in the prefabrication of reinforcement cages and subsequent concreting. Necessary adaptations in segment design are pointed out when welded reinforcement is used, and conceivable further developments are shown. The medium‐term goal is a continuous IT‐based production control system that allows short‐term adjustments to segment production, logistics and subsequent installation in the tunnel. [ABSTRACT FROM AUTHOR]

Transverse sliding of the 985 m long steel Lennetal bridge The Lennetal bridge is one of the major viaducts on the A45. Due to the increased traffic volume and the structural condition of the existing bridge, it was necessary to build a new bridge. In order to restrict traffic as little as possible during the construction period, the new superstructure was built for one direction of traffic in a lateral position and then moved to its final position by means of a transverse sliding. With a length of almost 1000 m, the Lennetal bridge is – in relation to the bridge length – the largest transverse sliding that has been realised in Germany so far. This paper deals with the special features of the planning and execution of the transverse sliding. [ABSTRACT FROM AUTHOR]

Mechanical material behaviour of ultra‐high‐strength structural steel S960QL in case of fire Due to their good strength‐to‐weight ratio, high‐ and ultra‐high‐strength structural steels are increasingly used in multi‐storey and industrial buildings in the form of plate material, pipes and sections. For structures with fire protection requirements, however, the use of high‐strength structural steels is currently inhibited by a lack of knowledge regarding temperature‐ and rate‐dependent material behaviour. Comprehensive knowledge of the material behaviour is a basis for a realistic modeling of the load‐bearing behaviour of steel structures. Within the framework of the FOSTA‐research project P 1502, systematic investigations of the structural material behaviour of ultra‐high‐strength steels are carried out in terms of an extensive tensile test program. The aim of the project is to characterise the mechanical material behaviour during all phases of a fire, including the cooling phase of natural fire scenarios. The paper addresses the material behaviour of quenched and tempered steel S960QL in fire. Steady state and transient state tensile test results are presented and used for the characterisation of the material behaviour during the heating phase of a fire and the comparison to common material models. In addition, the results of natural fire tests for the evaluation of the material behaviour in the cooling phase and the residual behaviour are presented. [ABSTRACT FROM AUTHOR]

Universal high‐performance columns made of high‐strength steels without welding In recent years, steel‐concrete composite columns made of normal‐strength steels are seldom used owing to the economic and technological advantages of precast reinforced concrete columns. Though, the use of high‐strength structural steels bears high potential for the efficient production of composite columns with excellent structural performance that are economically competitive to precast concrete columns, there are currently major obstacles to use of the ultra‐high‐strength steels (UHSS) in Germany. Hollow section composite columns with embedded high strength steel core without welded connections provide an opportunity to regain lost market share. A research project, funded by the AiF (Arbeitsgemeinschaft industrieller Forschungsvereinigungen), is intended to explore the potential of UHSS composite columns by experimental and theoretical investigations. The present paper demonstrates the concept of such composite columns with UHSS and gives first exciting insights into the research results. In addition to column tests under ambient and fire conditions, small scale tests are necessary to investigate various influencing factors and to create the basis for new and easy to use design and construction principles that allow efficient application. [ABSTRACT FROM AUTHOR]

Shape optimisation of eccentrically loaded columns – theory and experimental verification. In shape optimisation, the external shape of the structural component is adapted to the predominant force flow. In this way, large load increases can be achieved with the same material use, or high material savings can be achieved with the same load‐bearing capacity. In this paper, a shape optimisation for eccentrically loaded columns is presented, where the bending stress results from a frame effect of the load‐bearing system. This is the case, for example, in edge columns of typical reinforced concrete skeleton structures, as they are usually used in residential and commercial buildings. The shape optimisation method presented in the article can be applied to columns with an arbitrary ratio of a moment‐normal force loading, provided that a material failure occurs. Results for shape optimisation in the case of a stability failure have already been published separately for centrically pressed columns. The optimisation itself is carried out iteratively on a column segmented over the height under the criterion of achieving a uniform stress state in the component. With the help of an experimental check on 3.3 m high columns, the selected calculation and optimisation method could be verified. In addition to the failure loads, the concrete strains and the deformation behaviour were also analysed and evaluated at selected points of the specimen. [ABSTRACT FROM AUTHOR]

Punching shear in irregular flat slab systems – Recommendations for modeling and design The punching shear verification is often the decisive verification in design due to the concentrated load introduction. Moreover, uneven shear stress distributions often occur in the punching shear area as result of irregular flat slab systems or eccentric loads. In structural design it is often questionable, how a non‐uniform shear stress distribution can be considered with acceptable effort. The direct determination of the shear stress distribution along the control perimeters using FE methods is not explicitly excluded in the current Eurocode 2 but is also not described in more detail. This gives considerable freedom in design for the structural engineer, but also ambiguities for interpreting the results. In this paper, FE approaches for determining the factor β or for directly considering the non‐uniform shear stress distribution are presented and analyzed based on an application example. Finally, recommendations and modelling advice are given for the pragmatic and, as far as possible, realistic determination of factor β for consideration of unbalanced moments. [ABSTRACT FROM AUTHOR]

Digital education for geotechnical engineering: current status and further developments Digital teaching tools and materials have been used at universities (of applied sciences) for several years and open up new ways for higher education. However, depending on the type and intended quality, the creation of these teaching materials can be very time‐consuming and mean a lot of extra work for teachers. In a collaborative project to produce teaching videos for geotechnical field and laboratory experiments, the authors of this paper have experienced that a collaborative approach across university borders for the production of teaching materials has many advantages. Inspired by this collaboration, the authors of this report conducted a survey among German‐speaking geotechnical engineering chairs at (technical) universities and universities of applied sciences. After three semesters of mostly digital or hybrid teaching due to the Corona pandemic, one aim of this survey was to capture the use of digital teaching materials in the field of geotechnical engineering. Another goal was to initiate a network in which geotechnical engineering professors can exchange information on teaching topics and jointly create and use (digital) teaching materials. This article presents the authorś collaborative teaching project and the results of the survey conducted. Moreover, it reports on the first activities of the new network. [ABSTRACT FROM AUTHOR]

Validation of the AVISA model Despite advanced design technologies, construction on cohesive soils is still a challenge. Especially when dealing with cyclic loading conditions combined with the time‐dependent behavior of cohesive soils, such as offshore structures or even dams, the tools to predict the long‐term deformations of fine‐grained soil are limited. Due to the complex influence of loading rate, preloading, and soil structure, it is necessary to understand the effects of these influences on cohesive materials through laboratory testing and describe them numerically through accurate and physically based constitutive equations. Researchers (continue to) develop many hundreds of material models each year. Most of them are used for PhDs and not investigated further. In this work, such a model, developed in the first author's PhD, is be validated. The performance of the AVISA model has been previously demonstrated on experiments of various fine‐grained soils. In this paper, a new experimental study on Malaysia Kaolin is used for the validation of the model. Furthermore, the reproducibility of the so‐called Krey and Tiedemann criteria, parameters φ′s , c′ und φ′ is investigated by simulations of simple shear tests. It should be noted that many constitutive models for fine‐grained soils fail in this task. [ABSTRACT FROM AUTHOR]

During the planned conventional deconstruction of the Salzbachtal bridges, which were highway bridges of BAB 66 in the district Biebrich of Wiesbaden, a roller bearing collapsed on June 18, 2021. The superstructure laid on a pier and pushed it sideward; furthermore, cracks arose in the superstructure. As the structural safety could not be guaranteed, the bridge itself as well as the street Mainzer Straße and the Taunus railway line to Wiesbaden main station were closed. To clear the resulting significant traffic disturbance a blast demolition was planned and executed in a short notice. Due to the confined space and several infrastructure worthy of protection in the direct neighbourhood, the blast concept envisaged to blast the southern bridge by vertical collapse and to lay down the northern bridge by tilting collapse on the southern bridge afterwards. The blast demolition of both bridges was carried out on November 6, 2021 by 204 kg explosives. All piers of the southern bridge buckled to the west as planned and the superstructure fell down exactly vertically. The northern bridge followed 3 seconds later and tilted to the south. In this paper, the history of the original conventional demolition concept, the accident as well as the blast demolition concept and execution is described. [ABSTRACT FROM AUTHOR]

Until now no mandatory guidelines for the structural planning of the deconstruction of existing concrete structures are introduced by the authorities, which assist the planning engineers in the evaluation of these existing or damage structures. Often complex structural states of deconstructions have to be calculated, which depend on the knowledge of the actual structural condition. Therefore the only source of information is given by the existing documents, which often don't represent the actual state. To reduce the risks and to increase the planning and tender security, diagnostic investigations offer a big potential. Because not all information, as e. g. the knowledge about the possibility of a subsequent anchorage of cut prestressed tendons can be evaluated in advance of a deconstruction, further experimental investigations are necessary. As yet no technical or contractual rules are defined. The paper gives an overview of practical experiences and possible potentials of these experimental investigations. [ABSTRACT FROM AUTHOR]

An online platform for the management of digital visual data for the condition monitoring of protective coatings on marine steel structures The paper presents an online platform for the annotation and management of visual digital data, which allows for the condition monitoring and maintenance modelling of protective coatings of marine steel structures by means of digital image data only. A 10‐step procedure is introduced which includes the data acquisition, transfer of the data into the online platform, the annotation and management of the data by means of special tools and methods, and the modelling for condition monitoring and maintenance purposes. Some special applications of the platform are exemplary illustrated. [ABSTRACT FROM AUTHOR]

Experimental investigations on the durability of intumescent coatings Intumescent coatings are used in structural fire protection to improve the fire resistance of steel structures. Beside structural fire resistance also aesthetic demands can be fulfilled. The profile‐following application and the low dry film thickness of the products make it possible to maintain the filigree appearance of steel structures. In addition to the thermal protection effect, the durability of the coating must also be ensured. The assessment methods available at European level by EAD 350402‐00‐1106 aim to a service life of ten years. Test methods for a longer period are not described. This paper presents experimental investigations on the influence of weathering on the expansion behaviour, the thermal performance and the reactions taking place during foaming in case of fire. The tests were carried out on a water‐based and an epoxy resin‐based intumescent coating. The research results were obtained in the IGF research project 20470 N. [ABSTRACT FROM AUTHOR]

Blast demolition of Salzbachtalbrücken During the planned conventional deconstruction of the Salzbachtal bridges, which were highway bridges of BAB 66 in the district Biebrich of Wiesbaden, a roller bearing collapsed on June 18, 2021. The superstructure laid on a pier and pushed it sideward; furthermore, cracks arose in the superstructure. As the structural safety could not be guaranteed, the bridge itself as well as the street Mainzer Straße and the Taunus railway line to Wiesbaden main station were closed. To clear the resulting significant traffic disturbance a blast demolition was planned and executed in a short notice. Due to the confined space and several infrastructure worthy of protection in the direct neighbourhood, the blast concept envisaged to blast the southern bridge by vertical collapse and to lay down the northern bridge by tilting collapse on the southern bridge afterwards. The blast demolition of both bridges was carried out on November 6, 2021 by 204 kg explosives. All piers of the southern bridge buckled to the west as planned and the superstructure fell down exactly vertically. The northern bridge followed 3 seconds later and tilted to the south. In this paper, the history of the original conventional demolition concept, the accident as well as the blast demolition concept and execution is described. [ABSTRACT FROM AUTHOR]

Life Cycle Assessment in the Building Sector – Greenhouse Gas Emissions of Common Ceiling Systems In the past, life cycle assessments (LCAs) of buildings were only carried out in rare cases at the request of project initiators. Against the backdrop of social and political pressure to act more climate‐friendly and sustainably, LCAs and the available data are also becoming increasingly economically relevant. This paper therefore presents the essential principles of LCA in the building sector. In addition to a critical analysis of the scope of assessment, there is a brief presentation of available data bases, such as the national database ÖKOBAUDAT. Furthermore, the greenhouse gas balance of timber as a building material is discussed, which in some cases opens up considerable scope for assessment with the risk of false incentives. As horizontal building components, ceiling systems of multi‐storey buildings can cause almost 40 % of the structural emissions and are therefore highly relevant for a LCA. By varying the life cycle stages assessed and data sets used as possible factors influencing the results of a LCA, these building components are examined and compared in more detail in the following article. Despite some sensitive effects on the comparison of the ceiling systems, the LCA offers a decision‐making aid for the selection of ceiling systems in terms of reduced greenhouse gas emissions of a shell construction. [ABSTRACT FROM AUTHOR]

Internet of Construction: Potential of LoRaWAN quality assurance in the In‐situ concrete prozess Achieving high quality assurance standards when using in‐situ concrete requires a great amount of manual documentation. In particular, in‐situ concrete installation requires a great deal of attention, as the use of the right concrete in the intended building element must be ensured and errors mean additional time and costs. In other industries, it can be observed that IoT systems are already used profitably to support the execution processes and for documentation needs. However, despite the numerous digital solutions available, the use of Internet of Things (Iot) technologies for such monitoring tasks on the construction site are rarely observed. Yet the technologies have the potential to simplify quality assurance measures and make construction more attractive. This paper deals with the process step of concrete installation within the value chain of in‐situ concrete construction, which has so far been performed mainly manually, involves a high risk of error and is very time‐consuming to monitor. A Long Range Wide Area Network (LoRaWAN‐)‐based IoT system is designed to support humans in documenting the concrete installations. The system will then undergo a field test on a construction site. The results obtained are compared with the process‐related requirements, and with this it is shown that some important requirements are already satisfactorily fulfilled with the presented setup. [ABSTRACT FROM AUTHOR]

The structural condition as challenge for the deconstruction planning Until now no mandatory guidelines for the structural planning of the deconstruction of existing concrete structures are introduced by the authorities, which assist the planning engineers in the evaluation of these existing or damage structures. Often complex structural states of deconstructions have to be calculated, which depend on the knowledge of the actual structural condition. Therefore the only source of information is given by the existing documents, which often don't represent the actual state. To reduce the risks and to increase the planning and tender security, diagnostic investigations offer a big potential. Because not all information, as e. g. the knowledge about the possibility of a subsequent anchorage of cut prestressed tendons can be evaluated in advance of a deconstruction, further experimental investigations are necessary. As yet no technical or contractual rules are defined. The paper gives an overview of practical experiences and possible potentials of these experimental investigations. [ABSTRACT FROM AUTHOR]

KI/ML‐based Analysis and Interpretation of the IABSE‐Bridge Collapse Database Statistical analyses of bridge collapse data show that concrete bridges collapse significantly less frequently than bridges made of steel or wood. Since the main causes of bridge collapses worldwide are floods and associated fluvial processes, such as scouring, debris flows, etc. and impacts, it is reasonable to assume that the high dead load of concrete bridges leads to an overall more robust behavior in these events. This paper will examine whether the IABSE collapse database confirms this hypothesis and whether indications of further causes can be identified. For this purpose, the IABSE collapse database is examined using artificial intelligence and machine learning (AI/ML) methods. However, the AI/ML analysis does not confirm the previous thesis. The reasons for the rejection of the thesis, such as the representativeness of the data, are also discussed. An extension of the database for events with large numbers of collapses is recommended. [ABSTRACT FROM AUTHOR]

An UHPC for use in deep‐sea research The article deals with comprehensive material investigations carried out with an ultra‐high performance concrete (UHPC) intended for use in the deep sea. The tests performed include the determination of the stress‐strain behavior under uniaxial loading of the specimens, of the biaxial compressive strength of the UHPC under different stress ratios, of the tensile strength characteristics, and of the elastic modulus. Cubes, prisms and bone‐shaped test specimens were used for the investigations. From the determined material properties, conversion factors for the geometry‐dependent strengths of the concrete were calculated. In the paper, the determined biaxial compressive strength values are compared with data known from the literature. It is shown that an UHPC can have a similar increase in strength as a normal strength concrete. [ABSTRACT FROM AUTHOR]

Glacial soil deposits are present in Europe on both sides of the Alps, in Scandinavia, Northern Germany, Poland and in North America. There are typical names of the stages of the glaciation, however, the geotechnical characteristics of glacial deposits are similar in all regions; but are very heterogeneous locally. Glacial deposits extend from boulders to invisible silt particle (rock flour) and to clay particles, both of similar grain size. In this paper the focus will be on clean gravel without fines, so‐called open gravel and the challenges and solutions for tunnelling. Face support by pure bentonite slurry is insufficient in open gravel. Different techniques have been used in practice: clogging the pore channels with fines of appropriate gradation by controlling the content fines in the slurry. Use of high viscous slurry with increased clay or bentonite content. In another solution lime powder and polymers were added in the excavation chamber of an earth‐pressure shield to modify the ground. Other aspects such as muck disposal will be evaluated. [ABSTRACT FROM AUTHOR]

Projects Final major tunnelling contract awarded for Sydney Metro West / Letzter großer Tunnelbauauftrag für Sydney Metro West vergeben Implenia builds Boknafjord tunnel in Norway / Implenia baut Boknafjord‐Tunnel in Norwegen Contracts for main tunnel and materials management for second tube of Gotthard road tunnel / Verträge über Haupttunnel und Materialbewirtschaftung für zweite Röhre Gotthard Straßentunnel Greywacke – Rock of the Year 2023 / Grauwacke – Gestein des Jahres 2023 Carcassing work in the Albula Tunnel complete / Roharbeiten im Albulatunnel abgeschlossen Second tube of Long Itchington Wood Tunnel launched / Zweite Röhre der Long Itchington Wood Tunnels angefahren Shell construction of cross passages in Rastatt Tunnel complete / Querschläge im Tunnel Rastatt im Rohbau fertig Blast driving in Cholfirst safety tunnel started / Sprengvortrieb im Sicherheitsstollen Cholfirst gestartet North Portal of Brenner Base Tunnel is taking shape / Nordportal des Brenner‐Basistunnels nimmt Gestalt an New Wendlingen‐Ulm line goes into operation / Neubaustrecke Wendlingen‐Ulm in Betrieb Call for papers – Topics for the next issues of Geomechanics and Tunnelling / Themen für die nächsten Ausgaben der „Geomechanics and Tunnelling" [ABSTRACT FROM AUTHOR]

Development and testing of an urban green façade system for humans, flora and fauna This paper presents the climate‐regulating and biodiversity‐supporting potential and synergies of an innovative green façade system for humans, flora and fauna. The developed system opens up vertical habitats, especially for native plants, birds and insects, and creates climatic compensation functions for buildings and people. An interdisciplinary research methodology brings together the fields of (urban) building physics and ecology. The test results from the summer months of 2022 prove the contribution of the green surface to reducing heat input into the façade as well as into the surrounding area in comparison to a reference concrete wall. At the same time, the biodiversity (e.g. different insects) was significantly increased on the vertical by creating heterogeneous habitats and plant populations. Thus, the developed green system represents an innovative element for coping with complex requirements due to climate change, urbanization and species loss in the built environment and shows solutions for inclusive urban surfaces for humans, flora and fauna. [ABSTRACT FROM AUTHOR]

Mechanical activation of clay Known advantages of clay in building physics are moisture sorption and regulation, reduction of sound and heat storage capacity. Compared to other materials, clay has low mechanical properties. The paper focuses on mechanical activation of clay and relates to challenges in the production of clay‐based‐construction panels. It examines compressive and bending strength due to the process of milling, using a vibratory disc mill. The raw clay was sieved and for testing the fractions < 250 μm were milled. This milled clay was mixed in various compositions. Samples consisting of a mixture of milled fractions < 0,25 mm and non‐milled fractions 0,25 to 2 mm, a max. increase in compressive strength of 74 % was observed at a milling time of 60 minutes and for 20 wt.% water addition. Also, preliminary rheological tests (SAOS), which were carried out to follow the cohesion development over time of the clay pastes at different milling time, showed a max. of reactivity for samples which were milled 60 minutes. [ABSTRACT FROM AUTHOR]

Environmental Performance of Ceiling Systems in Building Construction – Currently used Systems and Future Optimisation Potenzial The building industry counts to the most influencing sectors regarding raw material demand, energy use and solid waste generation (≥ 38 %). The development and use of construction methods and building materials with minimal environmental impact over the entire life cycle has therefore utmost relevance. In order to quantify the environmental impact of construction methods and materials, a fact‐based life cycle assessment must be carried out. Currently, these kinds of assessments are not state of practice with a lack of objective comparisons missing on the market. When looking at building construction, ceiling systems in particular have a great influence on the environmental footprint of the entire building. Therefore, this paper is dedicated to the environmental comparison of different ceiling systems in building construction based on EN 15804 and EN 15978. The system boundaries were defined with the life cycle phases of cradle‐to‐gate and cradle‐to‐grave. A total of nine different ceiling types within different structural systems were considered and evaluated. All systems were dimensioned as efficiently as possible according to common engineering practice for the given boundary conditions with the currently valid standards (ÖNORM, Eurocode). The results show that environmental competitive systems can be implemented using all considered materials. The key is to take the materials properties into account while simultaneously optimising the structure and load‐bearing systems. [ABSTRACT FROM AUTHOR]

Tensile load‐bearing behaviour of concrete components with impregnated textile reinforcement made of natural fibres Recently, the use of natural fibres as a reinforcement in composite building materials have witnessed a growing interest amongst researchers due to their ecological, economical and mechanical properties. In civil engineering, however, they have not been considered in extensive investigations or the development of design guidelines for concrete members with textile reinforcement made of synthetic fibres. In this paper, the uniaxial tensile load‐bearing behaviour of concrete members reinforced with flax fibre textiles (impregnated leno fabrics) is investigated. Therefore, test specimens were casted and tested, varying parameters of the textiles, e. g., the spacing of the weft threads. For a reference, both test specimens reinforced with non‐impregnated textiles and without any reinforcement were investigated. The suitability of this type of reinforcement for concrete members under uniaxial tension is shown by an increase in the ultimate load compared to members without or with less reinforcement. The curves of the stress‐strain diagrams can be divided into three stages typical for reinforced tensile test specimens (state I – uncracked, state IIa – process of cracking and state IIb – completed crack pattern). The differentiation of the areas is clearer with an increasing reinforcement cross‐section. Further, a finely distributed crack pattern with uniform crack widths was observed which supports the findings of the diagrams. [ABSTRACT FROM AUTHOR]

Persönliches Nachruf zum Tod von Michael Gierga Veranstaltungen Internationales Xella Fachkolloquium: Wege zur Dekarbonisierung in der Baubranche Call for papers – 12. Symposium Experimentelle Untersuchungen von Baukonstruktionen (SEUB) Nachrichten Bundesbauministerin Klara Geywitz lobt Entwicklung der Seilroboter‐Technologie für den Mauerwerksbau Einreichen für das Jahrbuch Ingenieurbaukunst 2024 Ziegel – das Beste aus Mutter Erde [ABSTRACT FROM AUTHOR]

Simplified consideration of framing effects in masonry buildings Due to the increased requirements resulting from higher wind and earthquake loads, it is necessary to improve and optimise the calculation and design approaches for masonry structures. An important contribution to a better utilisation of the structural load‐bearing reserves is the consideration of the framing effects through the activation of the floor slabs in the calculation models, which has not been utilised in practice so far due to the complexity of the wall‐slab interaction. The paper presents a simplified approach based on the contributory slab width, which captures the essential influencing factors in parameterised tables. This provides structural engineers with a simple tool to exploit the frame load‐bearing effect in masonry design. [ABSTRACT FROM AUTHOR]

Design model for headed studs as shear connectors under additional tensile loading Headed studs are primarily subjected to shear when used as shear connectors in usual steel‐concrete composite structures. Consequently, initial design rules for shear connectors in composite structures did not address tensile forces directly. In case of horizontally lying headed studs embedded in a thin concrete slab such as in composite bridges, the headed studs may be subjected to tensile forces. For horizontally lying studs, current design rules consider a possible failure caused by a tensile load due to pull‐out by specifying geometric boundary conditions. As a consequence, relatively long shear connectors are required, which lead to uneconomical or impractical embedment lengths of the shear connectors. As meanwhile European code rules for fasteners under shear and tension (EN 1992‐4) have been developed, the upcoming Eurocode 4 refers to them for the design of shear connectors under combined tension and shear in composite structures. The fastening technology allows a direct design for tensile loading for different failure mechanisms, considering the influence of the reinforcement and concrete strength. Following this idea, this paper presents a design model for shear connectors in steel‐concrete composite structures under additional tensile loading based on experimental and numerical investigations considering recent developments in fastening technology. [ABSTRACT FROM AUTHOR]

Transversal load introduction into unstiffened girder webs – interaction with shear force and bending moment and implementation in new Eurocode version Transversal load introductions into unstiffened girder webs are often used economic solutions in building structures, not directly covered in the current Eurocode. Within this paper an engineering design model, developed at TU Graz, is evaluated for cases with additional high shear forces and bending moments acting at the girder. The resulting load carrying behaviour, in cases of interaction between Fz & Vz & My, is presented, based on comprehensive numerical studies, also for girders which are susceptible to web buckling. Finally, the modified design model is presented, which will be part of the new Eurocode version prEN 1993‐1‐1. In addition, a more general solution is shown, which could also be implemented in the Eurocode in form of a national Annex. [ABSTRACT FROM AUTHOR]

Radiography in civil engineering – practical applications of RT in NDT‐CE Radiographic Testing (RT) has been a proven testing method in NDT for decades. This is because RT is the only method providing direct imaging of the inner structure of welds, castings, and workpieces. However, radiography is widely unknown in the field of non‐destructive testing in civil engineering (NDT‐CE) in Germany – although great progress has been made in the last decades, especially in the field of digital imaging and mobile applications. This allows for many practical testing tasks, e. g. on‐site quality assurance, damage assessment, and non‐invasive investigation of buildings under a preservation order. In general, RT allows for identification, size and depth determination of reinforcement, tendon ducts and other components. Investigation and evaluation of cracks and corroding steel should be possible as well and may be the aim of future research work. This paper outlines basics, possibilities and limitations of radiography in civil engineering and shows its potential basing on practical applications. [ABSTRACT FROM AUTHOR]

Ductility‐increasing reinforcement systems for fabricated column elements made of UHFB In order to build faster, lighter and more precisely with concrete, a new modular construction concept based on ultra‐high performance concrete (UHPC) was investigated, which has a highly advantageous ratio of axial compression load‐bearing capacity and dead weight [1]. In order to enable proper manufacturing of this column element, which is referred to as a winding‐reinforced UHFB hybrid tube, in an automated extrusion process, a novel reinforcement concept has to be developed without the usual steel reinforcement. In an extrusion process, a supporting inner steel tube is encased with UHPC and advanced together with the UHPC. Subsequently, a ductility‐enhancing confinement reinforcement is applied to the surface of the components from the outside in a process that can be automated. As UHPC fragments damage the CFRP reinforcement in case of failure, this paper investigates which protective layer/reinforcement system can be used to achieve ductile component behavior for beam structures subjected to axial compression. For this purpose, different textile reinforcement layers were applied to UHPC specimens and their influence on the load‐bearing behavior of the components was determined with special consideration of ductility and residual load‐bearing capacity after exceeding the maximum load. A combination of aramide fabric and carbon fiber textile showed favorable load‐bearing behavior with enhanced quasi‐ductility in experimental investigations. [ABSTRACT FROM AUTHOR]

Failure criteria for foam‐grouted gravel under multiaxial loading Foam grouting is an innovative method for improving the mechanical properties of cohesionless, coarse‐grained soils. Despite this, only a few experimental studies have been conducted to assess the failure of foam‐injected soils under multiaxial loading. This paper aims to fill this gap in knowledge. The stiffness and strength of the natural soil, which serve as reference values for the evaluation of the improvement effect due to the injection, are derived from drained triaxial tests. The mechanical behaviour of the foam‐injected soil is investigated using uniaxial, triaxial, and splitting tensile tests. The foam‐injected soil, exhibits significantly higher strength and stiffness but lower ductility than the untreated soil. The ductility of the foam‐injected soil increases with increasing lateral pressure. The splitting tensile strength is only a small fraction of the compressive strength. The adequacy of the failure criteria Mohr‐Coulomb, Hoek‐Brown and Lade for the description of the failure of foam‐injected coarse‐grained soils is verified. All three failure criteria are basically suitable to describe the state of failure in triaxial compression. For compressive and tensile loading, the Hoek‐Brown and Lade failure criteria seem to be more appropriate compared to Mohr‐Coulomb. [ABSTRACT FROM AUTHOR]

Investigation of the withdrawal capacity of thread‐optimized wood screws The withdrawal capacity is necessary for the design of screws for application in timber, so called wood screws. The withdrawal capacity is influenced by the thread geometry of the screw which interact with the wood properties. Prior investigations have not been able sufficiently determine the influence of the thread parameters on the withdrawal capacity to enable thread geometry optimization. In investigations with so‐called thread‐test‐objects with straight thread flanks, the influences of thread parameters were determined. However, the transferability of these results to wood screws is still unclear. Aim of this paper is to investigate this transferability. To do so, various thread geometries optimized for withdrawal capacity were designed. To test the transferability of the results, the withdrawal capacity of two screw variants with optimized thread geometries, a reference variant and a commercial wood screw is measured. The two optimized screw variants show significantly higher withdrawal capacities compared to the reference variant and the commercial screw variant. This demonstrates that the findings based on the thread‐test‐objects are transferable for the design of wood screws. Manufacturers can therefore use these to optimize the wood screw geometry. [ABSTRACT FROM AUTHOR]

Persönliches Nachruf auf Hans Peter Tzschucke Nachrichten Modellfabrik für Carbonbeton in Leipzig eröffnet Wettbewerbe bauma Innovationspreis 2022 Veranstaltungen Call for papers – 12. Symposium Experimentelle Untersuchungen von Baukonstruktionen (SEUB) 40. Deutscher Stahlbautag in Berlin [ABSTRACT FROM AUTHOR]

Parametrization in bridge construction for the application of artificial intelligence For the application of digital methods in the execution phase, the acquisition of exisiting structures or the construction progress with the aid of LiDAR is a suitable method to subsequently detect components as automatically as possible and e. g., to evaluate them for construction progress monitoring. Machine learning methods are suitable for component detection and are used for various classification problems. One problem is the semantic segmentation of point clouds, in which the individual points are assigned to specific component classes. To solve the segmentation with sufficient accuracy and to make predictions on real data, a large amount of training data is needed. This process is also called "Scan to BIM". In this paper, synthetic data for training a convolutionalneural network (CNN) is provided in a highly parameterized and fully automatic way. An approach for generating variations of bridge models based with the visual programming interface Dynamo in Autodesk Revit is proposed. At the beginning, guidelines for the definition of parameters are evaluated to subsequently use them in adaptive templates. Attributes are assigned to each component and grouped into a feature structure when exported to the IFC data format. This approach resulted in numerous variations of bridge models that can be used for semantic segmentation of point clouds and training of a CNN. [ABSTRACT FROM AUTHOR]

Penstocks with multiple thrust rings – accurate forces at thrust rings due to constraining effects and comparison with a simple design model Thrust rings are a component of penstocks and have to transfer the longitudinal forces of the steel pipe to the surrounding rock mass. Longitudinal forces occur primarily due the pressure loads at valves or at pipe covers. Within this paper, the realistic load bearing behaviour of different penstocks geometries with multiple thrust rings is presented, including constraining effects due to internal pressure and temperature. Results are shown with and without friction effects between steel pipe and surrounding concrete and are based on numerical FE analyses. In addition, a simple 1D beam model (design model), developed by the authors, is presented. The forces at the thrust rings are compared between both models. It is shown that also for different load combinations the simple 1D beam model gives accurate results for practical application. The FE study also shows, that always the load combinations with the constraining effects due to internal pressure and temperature must be analysed – a superposition of the results of the individual load cases leads to misleading results. [ABSTRACT FROM AUTHOR]

Projects First TBMs launch in London for HS2 project / Erste TBMs in London für das HS2‐Projekt gestartet Breakthrough in the Kerenzerberg tunnel / Durchschlag im Kerenzerbergtunnel The Inn district power station has been put into operation / Gemeinschaftskraftwerk Inn in Betrieb genommen New schedule and cost plan for 2nd Munich main line / Neuer Zeit‐ und Kostenplan für 2. Stammstrecke München Contract awarded for the Wendlingen Tunnel on the new Stuttgart–Ulm railway line / Tunnel Wendlingen auf der Neubaustrecke Stuttgart‐Ulm vergeben All tunnelling work in the Stuttgart basin has been completed / Alle Tunnelvortriebe im Stuttgarter Talkessel beendet Sustainable pilot project in the Filder Tunnel uses cement‐free building materials / Nachhaltiges Pilotprojekt im Fildertunnel setzt auf zementfreie Baustoffe Herrenknecht AG wins bauma innovation award 2022 / Herrenknecht AG gewinnt bauma Innovationspreis 2022 Events Award ceremony for the international Mining the Future competition / Preisverleihung für den internationale Wettbewerb Mining the Future People Obituary Dipl.‐Ing Guntram Innerhofer / Nachruf Dipl.‐Ing Guntram Innerhofer Call for papers – Topics for the next issues of Geomechanics and Tunnelling / Themen für die nächsten Ausgaben der „Geomechanics and Tunnelling" [ABSTRACT FROM AUTHOR]

Nachrichten NEWood – ein kreislaufgerechter Baustoff Der Baugrund als digitaler Zwilling Tagungen & Veranstaltungen Brückenbautage am 10. und 11. November in Düsseldorf Veranstaltungen 4. Symposium Ingenieurbaukunst – Bauen mit und im Bestand 21. Internationale Baustofftagung – Call for Papers [ABSTRACT FROM AUTHOR]

The Erasmus+ project, entitled 'Digital Erasmus – a roadmap to using building performance simulation to achieve resilient design' (DesRes), seeks to transform the learning experience of students in built environment disciplines using a continuous digital learning cycle. Three universities play a part in this project: Graz University of Technology (TU Graz), Delft University of Technology (TU Delft) and the University of Strathclyde (UoS), each developing and delivering a module to complete the learning experience in building simulation. This paper describes the aims and learning objectives associated with the workshops taught at TU Graz as part of the module dedicated to energy monitoring. These workshops tackle the complexity of working with large data sets, which commonly arise from energy monitoring research. In particular, the workshops aim to provide a practical understanding of how to identify, handle, reshape, clean up and evaluate important summary statistics from incomplete data sets. These are fundamental skills in building simulation where model validation and calibration are increasingly commonplace. [ABSTRACT FROM AUTHOR]

Personal control has a considerable impact on individual perception of the indoor climate. This paper's objective is to shed more light on the perception of personal control at office workplaces by analysing: 1) the impact of perceived control on perception of indoor climate, 2) the effect of office type and season on level of control perceived, 3) objectively available adaptive opportunities; 4) subjective perception of their availability; 5) occupants' desire for certain adaptive opportunities; 6) how often and which controls were exercised; and 7) reasons for not exercising available adaptive opportunities. New variables were introduced: i) consistency of perception of controls and ii) conformity to expectation of controls, and their correlation with the level of personal control perceived hypothesised. A longitudinal survey was carried out in three office buildings (two mixed‐mode, one free‐running) in the hot‐summer Mediterranean climate of Amman, Jordan during four seasons. Indoor climate perception correlates positively with perceived control. Office type affects level of perceived control but not season. Most frequent stated reason for not exercising available adaptive opportunities was 'no need to change'. In this study, perceived control is not correlated with consistency of perception of controls but correlated with conformity to expectation of controls. [ABSTRACT FROM AUTHOR]

Data‐based improvement of energy consumption and indoor climate in public buildings – Literature study with focus on the success of approaches Reducing the energy consumption of public buildings is particularly important for achieving climate targets because of the exemplary role they play. A comfortable indoor climate and clean indoor air are crucial for the well‐being and health of building users. Rapid developments in sensors as well as in the fields of data analysis and simulation have led to increasing attempts to achieve improvements in energy consumption and indoor climate using data‐based approaches. The momentum has increased so much that it is becoming increasingly difficult to keep track of which approaches are applied in which situations and with what success. This paper presents a literature study that addresses this issue. For the study, 91 peer‐reviewed articles published between 2014 and 2022 were examined. It was found that the importance of indoor climate in data‐based approaches is increasing compared to that of energy consumption, building‐model‐based simulations are used with increasing frequency, articles deal with very specific issues, and an end‐to‐end consideration that also takes building users into account is usually omitted. [ABSTRACT FROM AUTHOR]

Automated post weld treatment for offshore wind turbines A more economical and resource‐saving construction of offshore wind energy converters (OWEC) is necessary in order to implement climate policy objectives. The increase of the fatigue resistance by using high‐strength steels and by applying post‐weld treatment methods offers great potential for reducing the use of materials and costs for monopiles. Specifically, in the automated OWEC manufacturing chain, automated processes such as deep rolling are a suitable option. Deep rolling is an established process in mechanical engineering for increasing the wear and fatigue resistance of metallic components. This paper presents results of deep rolling as a new post treatment method to increase the fatigue strength of welds. The surface and subsurface zone properties of submerged arc welded butt joints made of a structural steel grade S355MLO before and after deep rolling are shown. In order to quantify the influence of deep rolling on the weld geometry, measurements of a laser line sensor are presented. Finally, the results of fatigue tests are discussed, which show the great potential of the deep rolling process as a post weld treatment method. [ABSTRACT FROM AUTHOR]

Persönliches Rolf Eligehausen – 80 Jahre Manfred Keuser – 70 Jahre Zum 65. Geburtstag von Carl‐Alexander Graubner Nachrichten Bayerischer Denkmalpflegepreis 2022 verliehen Schülerwettbewerb Junior.ING startet 4. Symposium Ingenieurbaukunst – Bauen mit und im Bestand Call for papers Bestandsaufnahme zum nachhaltigen Bauen mit Beton Lieferengpässe und Preisanstiege bei Ausgangsstoffen [ABSTRACT FROM AUTHOR]

Automated Damage Classification on Concrete Bridges Using Convolutional Neural Networks Against the background of an ageing structure stock and the constant increase in heavy traffic, frequent structural inspections of high quality are indispensable. In accomplishing this task, the use of digital methods within the framework of digitized inspections (DIs) offers great potential for improvement in terms of cost‐effectiveness and quality. An essential component of DIs is the automated detection of damage with Convolutional Neural Networks (CNNs). As part of the research project "Model‐Based Digital Structural Inspection – MoBaP", CNNs are being trained at the University of the Bundeswehr Munich for the classification of defects occurring on concrete bridges. On this domain's currently largest open‐source dataset (CODEBRIM), the best CNN achieves an exact match ratio of 74 % and thus currently defines a strong baseline. In order to also train neural networks for object detection and semantic segmentation in this domain, a separate dataset is created. This enables not only the classification but also the localisation of damage on images. In this paper, the authors discuss the procedure of training neural networks for the classification of defects on concrete bridges and show a detailed analysis of test results. In addition, the development and current status of their own dataset is presented. [ABSTRACT FROM AUTHOR]

Explainable Domain‐Specific Artificial Intelligence for Bridge Engineering and Design The use of artificial intelligence (AI) is currently being discussed and evaluated across the board in research and practice in all industries. This paper first provides the necessary background knowledge on general AI and then elaborates the necessity of developing domain‐specific AI as well as explainable AI (XAI) for the calculation and design practice in civil engineering. The role of the civil engineering domain at the interface with AI in terms of data and modeling and design philosophy is discussed. The three examples of (i) computation of Kirchhoff slabs with physics‐informed neural networks, (ii) calibration of prior models for parametric bridge design from databases, and (iii) AI‐assisted conceptual design of bridges illustrate the application of domain‐specific machine and deep learning and XAI with special focus on concrete and bridge design. In particular, physics‐informed AI (piKI) represents an alternative to established numerical methods with special consideration of available simulation and experimental data and becomes explainable and comprehensible via the use of XAI. This paves the way for the use of piKI models in civil engineering as digital twins of a structure over its life cycles. [ABSTRACT FROM AUTHOR]

Climate Compatibility as a Criterion for the Design and Performance of Concrete illustrated by the Example of an ÖBB Small Animal Passage Concrete is the world's most widely used building material and is preferred for infrastructure construction inter alia due to its high performance, versatility and durability. Its production and use, however, generates significant amounts of greenhouse gas emissions (CO2eq). Consequently, any reduction of CO2eq of the building material contributes to achieving the societal goal of CO2 neutrality. In this paper, a small animal passage of an ÖBB railway line is used as an example to show how climate compatibility or CO2‐equivalents (kg CO2eq/m3) are directly integrated into the mix design. It is also explained how the essential performance characteristics of climate‐compatible concretes – in addition to the CO2‐equivalents, in particular their early strength and durability – can be considered and optimised in their entirety. For this purpose, performance‐based concepts are applied for the optimisation of binders with combined additives and for the verification of durability. Furthermore, experiences with the realization, testing and quality assurance of CO2eq‐reduced concrete in comparison to equivalent standard concrete will be reported. [ABSTRACT FROM AUTHOR]

Projects Tunnelling work for the Obervellach II power station has been completed / Vortriebsarbeiten für Kraftwerk Obervellach II abgeschlossen Refurbished Bosruck tunnel is fit for the future / Sanierter Bosrucktunnel ist fit für die Zukunft Opening of the refurbished Belchen tunnel / Eröffnung des Sanierungstunnels Belchen Start of tunnelling for the BBT H41 "Sill Gorge – Pfons" contract section / Tunnelanschlag im BBT‐Baulos H41 Sillschlucht‐Pfons Tunnel boring machine started in Göschenen / Tunnelbohrmaschine in Göschenen gestartet Manufacturing of test element for the Fehmarnbelt Tunnel successfully completed / Erfolgreiche Fertigung eines Testelements für den Fehmarnbelt‐Tunnel Pilot project for renewal of the Elleringhausen Tunnel / Pilotprojekt zur Erneuerung des Elleringhausener Tunnels Construction of Hamburg's district heating tunnel gets underway / Baustart für Hamburgs Fernwärmetunnel Deutsche Bahn submits planning for Offenburg Tunnel ‐ Deutsche Bahn reicht Planung für Tunnel Offenburg ein Entire route of the new section of the Brenner North feeder now established / Gesamtverlauf der Neubaustrecke Brenner‐Nordzulauf steht fest Contract awarded for Gotthard main northern section / Gotthard Hauptbaulos Nord vergeben Call for papers – Topics for the next issues of Geomechanics and Tunnelling / Themen für die nächsten Ausgaben der „Geomechanics and Tunnelling" [ABSTRACT FROM AUTHOR]

Great importance is attached to 'pressure‐volume records' for the execution, documentation and billing of rock grouting. In this context, special digital data management systems are now available which can provide data in a structured and consistent format that is also suitable for artificial intelligence (AI) approaches. Using datasets from a tunnel project in Scandinavia, this paper shows that artificial neural networks can be used to reliably predict the evolution of pressure‐volume records or the volume of grout injected at the end in the interests of construction site efficiency. Taking into account the technical feasibility of using AI to support tunnel grouting, we then show which contractual modifications would be required in order to make effective use of corresponding developments. [ABSTRACT FROM AUTHOR]

The Rudolf‐Fettweis hydropower plant, owned and operated by EnBW Energie Baden‐Württemberg AG, is situated in the Murg valley in the Northern Black Forest. The construction of a new underground Lower Basin is planned to upgrade the existing hydropower station. The in‐situ rock mass consists of Forbach Granite with local weakness zones, as encountered in the boreholes. Considering the extent of the project area, a 3D geological prediction model was used to allow a better interpretation of the spatial relationships of weakness zones in the rock mass and to optimize the orientation of the underground caverns. Adverse effects for the public were counteracted at a very early stage, so that the project received a high level of public acceptance. The present paper describes the current state of the project. [ABSTRACT FROM AUTHOR]

Various methods have been developed in recent decades to predict hazards associated with karst voids in underground construction. Common to all these methods is that the predicted range of water inflow is often insufficient for the purpose of implementing the planned construction works. This is usually due to an incomplete knowledge of the karst conduit system within a project area, making it difficult to predict the position and characteristics of karst voids. The method presented in this paper permits a robust prediction of karst water inflow. It is based on a combination of stochastically generated, pseudo‐genetic karst conduit systems and hydraulic modelling of the hydrogeological conditions using a Monte Carlo approach. This approach facilitates a plausible estimation of the expected range of karst‐induced water inflows and also enables the probability of encountering a karst voids. to be determined. The predictions allow for differentiated treatment of the hazards associated with karst water during the construction and operation phase of underground structures. In concrete terms, this relates to the planning and implementation of exploratory measures and ground‐improvement measures, the design of the dewatering system and its monitoring during the construction and operation phase. [ABSTRACT FROM AUTHOR]