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Translation abstract Deformation monitoring of bridges applying remote sensing satellite radar measurementsDeformations of the Earth's surface can be measured from space using remote sensing radar interferometry (InSAR). This paper demonstrates the use of these data for deformation monitoring on the Schottwienbrücke‐S6 Semmering motorway. The European Space Agency (ESA) recently began providing free research satellite data from the Sentinel‐1 mission. The approach uses historically recorded natural reflection points as well as corner reflectors artificially attached to the structure. These are measured coordinately and analyzed using remote sensing methods. Thermal displacements of the structure are compensated to increase accuracy. A new model predicts the temperature of the structure based on network weather data. This means that the deformation measurements from the satellites can be analyzed and thermally compensated without sensors on the building, and the deviations can be more than halved. The recorded and processed annual measurements from 2022 onwards show a standard deviation of 1.7 to 3.0 mm compared to the reference system (Liquid Leveling System). Good agreement with the long‐term settlement behavior of the bridge was also found for natural reflection points. Satellites can also be used to simultaneously record different structures at 6‐day intervals up to 2016. Due to the time‐delayed processing, they are currently well suited for long‐term deformation monitoring of long‐span bridges. [ABSTRACT FROM AUTHOR]

Translation abstract Legitimation of circular timber constructionThe sustainability principle requires that only as much wood is removed from the forest as will grow back in the same period. The annual harvest volume available for use in construction is therefore limited, also in view of the fact that other sectors of the economy are increasingly relying on the raw material. Accordingly, the aim is to maximise carbon storage as the sum of the carbon bound in the forest and the material use of wood. For the construction industry, this means maximising the longevity of building components by using wood as a resource in a circularly effective way. On the one hand, this paper presents the strategic approach to increasing the circularity of timber construction. On the other hand, the climate‐relevant proof of the necessity of circularly effective construction is provided and demonstrated using a dynamic balancing method. For this purpose, it is shown for resource consumption and global warming potential how circularly effective construction can be quantified in principle and in particular with wood. [ABSTRACT FROM AUTHOR]

Summary The significant cultural achievement of the development of the cultivation of Coca (Erythroxylum coca) by the indigenous South Americans was never adequately recognised by the European Conquerors. The aim of this paper is to demonstrate its importance for Western science by summarising its perception during the colonial period and the 19th century and reviewing the isolation of cocaine, its use as local anaesthetic, determination of its chemical structure and synthesis of substitutes as milestones of Western chemistry, pharmacy and medicine. Finally, it summarises the culturally impact of cocaine on the Western culture during the 20th century and the economic impact of coca production in South America. [ABSTRACT FROM AUTHOR]

According to a traditional interpretation of Kierkegaard, he endorses a strong form of direct doxastic voluntarism on which we can, by brute force of will, make a “leap of faith” to believe propositions that we ourselves take to be improbable and absurd. Yet most leading Kierkegaard scholars now wholly reject this reading, instead interpreting Kierkegaard as holding that the will can affect what we believe only indirectly. This paper argues that Kierkegaard does in fact endorse a restricted, sophisticated, and plausible version of direct doxastic voluntarism. On Kierkegaard's view, when we take ourselves to be in an epistemically permissive situation, we have the ability to form outright beliefs (but not credences) at will in virtue of our ability to voluntarily 1) open or close inquiry and 2) determine our attitude towards epistemic risk. [ABSTRACT FROM AUTHOR]

This paper presents an overview of the contents of 2nd Generation Eurocode 7 Part 2, highlighting two of the major changes introduced, being the Ground Model and the Rock Engineering implementation. The document is organized from a ground property perspective so that the role of Part 2 and the links with the geotechnical design are much clearer than in the previous edition. Its new title is a clear indication of this idea: "Ground properties" including both soil and rock properties. The need to have representative values for the ground properties is the objective of this new Part 2, which is intended to guide designers on the path to obtain those values by means of the Desk Study, Site Inspection, Field Investigation and Laboratory Testing. Given this framework, the paper explains the concepts behind the Ground Model, the main output of the Ground Investigation, which includes the ground profile, the geometric properties of the ground and its layers, groundwater, and the derived values of the ground properties, paying attention of the role of discontinuities in such ground profile. The tasks that form the Ground Investigation and the minimum number of activities to be performed are described. This new version of EN 1997 will include a Rock Engineering perspective for all above items. And finally, the ground properties of the rock material and the rock mass are listed and discussed. [ABSTRACT FROM AUTHOR]

The current first generation of Eurocodes is a suite of ten European standards for the design of buildings and civil engineering works, whose implementation started in 2010. EN 1990 sets the basis of structural design, with the other Eurocodes dealing with different materials and specific aspects of design. Geotechnical aspects of design are covered by EN 1997 "Geotechnical design", usually called Eurocode 7. The evolution of the Eurocodes started in 2012 and the main objectives of their revision were to incorporate improvements that reflect the state‐of‐the‐art in engineering design and the needs of the civil engineering market, to improve the ease‐of‐use and to harmonize practice between countries. While the original version was developed largely based on soil mechanics, the aim was that the revised version treats soil and rock on an equal basis. The second generation of the Eurocodes is now nearly finished, and the revised EN 1997 is expected to be formally approved in 2024. This paper is the first of a set of six informative papers on the revised Eurocodes and rock engineering, prepared by members of the Rock Engineering Platform of CEN/TC250/SC7, a group of rock engineering experts that has been assisting in drafting EN 1997 from a rock‐engineering perspective. The paper presents the main changes to EN 1990 and EN 1997 as far as they affect geotechnical and rock engineering design. [ABSTRACT FROM AUTHOR]

Image‐based quality control – part 2: granulometric properties The changes in concrete technology necessary to achieve the climate protection targets will lead to a significant change in the concrete mixtures typically used. The raw materials used are becoming more diverse and complex. The use of recycled raw materials will also significantly increase the fluctuations in the properties of the raw materials. An Accurate and time‐efficient determination of the granulometric properties of the aggregate is of crucial importance, especially for "eco‐concretes", in order to ensure consistent quality characteristics. As a natural raw material, the aggregate is subject to certain fluctuations to which such optimized concrete compositions can react relatively sensitively. In the future, it will be necessary to determine possible quality deviations of the fresh concrete resulting from fluctuations in the raw materials in a time‐efficient manner in order to be able to make appropriate adjustments in the production process as quickly as possible. This paper presents an image‐based quality control for the digital evaluation of granulometric properties of the aggregate as a part oft he flow table test. Accordingly, the range of properties of the image‐based method already presented in Part 1 of this paper is extended to a fully comprehensive digital quality control. This paper presents the image‐based determination of the granulometric properties of the aggregate as a part oft he flow table test. The determination is based on the image‐based quality control described in part 1 of this paper. [ABSTRACT FROM AUTHOR]

Machine learning for design and analysis of steel frame halls The use of digital tools in design and construction processes increases efficiency, especially for recurring tasks and processes, such as the dimensioning of components or structures, which follow similar patterns. This paper develops an artificial intelligence (AI)‐based assistant for use in the pre‐design and design of steel frame halls as a prototypical co‐pilot. For this purpose, the necessary database of steel frame halls is first compiled from project archives of TRAGRAUM Partnerschaft Beratender Ingenieure mbB. This will be examined in the context of data analyses according to the decisive description parameters and similarities, so that finally suitable AI surrogate models for the prediction of the hall parameters are trained by means of regression analyses. Furthermore, an interface to the finite element program SOFiSTiK is implemented, which passes the predictions of the AI regarding the parameters of the steel frame halls to a parameterized input file and triggers the calculation and design. In the course of the calibration of the AI substitute models, in addition to the approximation qualities, possible safety margins to be provided are also discussed in the context of this article. This article shows that the prototypical co‐pilot for the preliminary design of steel frame halls could be successfully implemented. Furthermore the AI newly generated hall frames can be classified as stable with respect to the validation considerations. An outlook on future further developments of this approach as well as the transfer to other applications complete this paper. [ABSTRACT FROM AUTHOR]

Free‐form reinforced concrete, prestressed concrete and composite components: Calculation of cross‐section values A resource‐efficient use of concrete as a construction material can be achieved by adapting the individual shape of a component under consideration to the stresses that occur and by arranging composite construction materials (e. g. reinforcing steel, prestressing steel or structural steel) in suitable areas of the component. Due to the advancing digitalisation in the construction industry, for example in the context of Building Information Modeling, computer‐aided 3D modelling methods are increasingly being used in the planning of structures. These allow engineers to design components in free form. In reinforced concrete, prestressed concrete and composite construction, the design of such components is currently still associated with great effort. In the context of the development of a practical method for the calculation of free‐form concrete components, this paper presents a CAD‐integrated method for the calculation of cross‐section values. Cross‐section values are required as an essential calculation basis when real, three‐dimensional structural components are treated using simplified calculation theories, such as the beam theory. In this paper, the mathematical and numerical fundamentals of a method for the calculation of cross‐section values of free‐form concrete, reinforced concrete, prestressed concrete and compound components are presented. The calculation method is based on flat geometric regions described by Non‐uniform rational B‐Spline tensor product surfaces, which can be extracted from solid models, for example. [ABSTRACT FROM AUTHOR]

Modelling of the CUBE's TWIST shell This paper gives an overview of the main procedures prepared during the phase of the project development within the field of numerical modelling and design. The roof shell elements represent itself twisted shape that together with complicated structurally demanded inner structure forms quite complicated configuration for the concrete volumes as well as for the used reinforcement. Therefore, custom developed numerical method was required to be prepared. For that, the software solutions Rhinoceros 3D and Grasshopper 3D were used as the main algorithmic environment. The paper additionally gives an insight of important aspects required for production of the formwork components, thermal insulation, biaxially oriented carbon reinforcing grids and other parts of the load‐bearing shells. Finally, the paper gives an idea how was established a collaboration with partners of the CUBE project in particular in the field of structural analysis. [ABSTRACT FROM AUTHOR]

A mechanically consistent approach for stability verification of timber beams in compression and bending around the strong axis, part 1 – derivations Slender timber beams in bending can be designed using different methods in view of out‐of‐plane stability. Lateral torsional buckling may be verified either using the so called equivalent member method or by means of 2nd order calculations, considering equivalent imperfections. However, at present determining the lateral torsional buckling resistance using either of these both methods, leads to different results. In this paper, the background of both verifications is investigated in deep. Moreover, as an alternative approach, a non‐linear calculation with an imperfection shape in affinity to the critical shape is presented in part 1 of this paper. If the curvature amplitude is scaled, the same results as by the equivalent member method are achieved. It is shown that plasticity effects can be considered with high precision as well. In part 2, results of experimental tests on lateral torsional buckling of glued laminated timber and laminated veneer lumber beams are presented, with nearly ideal boundary conditions and load remaining vertical through‐out the test. Based on these test first tentative values can be obtained for the imperfection compatible with the alternative lateral torsional buckling approach presented. [ABSTRACT FROM AUTHOR]

Projects Tunnel construction work in the BBT Eisack underpass construction lot completed / Tunnelbauarbeiten im BBT‐Baulos Eisackunterquerung abgeschlossen Planning process for Frankfurt Inter‐city railway tunnel shortened / Planungsprozess für Fernbahntunnel Frankfurt beschleunigt Operational exercises before commissioning of the Koralm Railway / Einsatzübungen vor Inbetriebnahme der Koralmbahn Limberg 3 – Heavy transport in the mountain / Limberg 3 – Schwertransporte im Berg Second underground lot awarded for Hamburg U5 / Zweites U‐Bahnlos für Hamburger U5 vergeben Ligerz tunnel contract awarded as part of the Ligerz‐Twann double‐track extension project / Tunnel Ligerz im Rahmen des Doppelspurausbaus Ligerz‐Twann vergeben Max Bögl commissioned to produce and deliver segments for the Brenner Base Tunnel / Max Bögl mit Produktion und Lieferung von Tübbingen für den Brenner Basistunnel beauftragt Final breakthrough for the Silvertown Tunnel / Finaler Durchbruch für den Silvertown‐Tunnel STRABAG UK opens precast tunnel segment plant in Hartlepool / STRABAG UK eröffnet Fertigteilwerk für Tunnelsegmente in Hartlepool Extensive diaphragm wall work for Jakarta metro station / Umfangreiche Schlitzwandarbeiten für U‐Bahnstation in Jakarta Call for papers – Topics for the next issues of Geomechanics and Tunnelling / Themen für die nächsten Ausgaben der „Geomechanics and Tunnelling" [ABSTRACT FROM AUTHOR]

The current Eurocode revision process is sought to improve Eurocode 7 for application to rock engineering, while including only techniques and procedures that are in widespread customary use. The revision process has exposed much about the application of the Eurocodes to rock engineering, thereby offering hints as to what material should be included in the next revision – tentatively suggested for publication in 2035. Crucially, ideas have developed about how rock engineering practice may need to develop to embrace the principles on which the Eurocodes are based. In particular, aspects of determining the properties of rock masses, and design verification by observational methods, partial factors, numerical modelling, and prescriptive rules are all thought to require significant improvement or dramatic modification. This paper highlights challenges identified regarding the application of the Eurocodes to rock engineering, and which will need to be addressed in the future. Ideas are presented about how these challenges may be overcome, but these are given in the spirit of stimulating ongoing conversation within the rock mechanics and rock engineering community rather than presenting definite proposals. [ABSTRACT FROM AUTHOR]

In 2025 the new generation of the Eurocode 7 will be introduced and set a framework for geotechnical design for the next 20 years. As Eurocode 7 is an essential design code, the changes will affect numerous practising geotechnical Engineers. The paper provides an overview of significant changes in rock engineering design introduced in the new EN 1997 part 3, considering limit state design, durability, reliability, testing and other crucial design aspects. It focuses on the anchor clause revision and first introduced design rules for rock bolts and soil‐nailed structures. The improvements described include distinguishing between different tension supporting elements that have often been confused. Furthermore, the provisions for groundwater control measures influencing the working condition and limit states for all other geotechnical systems that have not yet been comprehensively addressed in the current Eurocode 7 are also clarified. Finally, the design of the described geotechnical structure will also be strongly affected by changes in the overall philosophy of the Eurocodes, which is also explained. [ABSTRACT FROM AUTHOR]

The second generation of Eurocode 7 includes both soil and rock. In addition to the current practice of ground engineering, this document aims at incorporating rock engineering, improving the ease of use, the harmonization of regulations and covering new developments. This paper provides an overview of some of the significant changes to Eurocode 7 in rock engineering design, taking into consideration limit state design, robustness, durability, and reliability. It focuses on the design of slopes, spread foundations, and retaining structures. The clauses focus on soil mechanics, but also include special rock mechanical issues such as the influence of discontinuities and strength anisotropy on the limit states. Many matters associated to verification of rock mechanical design are linked to the use of prescriptive rules and shall be given in National Annexes. For geotechnical structures in rock, it is mentioned that geotechnical mapping and documentation is important to verify the limit states. However, the basic issues with partial factor methods for verification of the ground‐structure interaction of reinforced slopes and retaining structures are not fully resolved. This has caused some difficulties in setting up partial factors and obtaining a sufficient overview of the application of partial factor method, especially in rock engineering. The design of slopes, spread foundations and retaining structures must likewise consider other clauses in the Eurocode. Rock support for slopes and retaining structures is described in Clause 13 "Rock Bolts and Surface Support". Groundwater‐related issues are described in clause 12 "Ground water control" which influence the design and limit states for the actual geotechnical structure. Dams and levees are featured in Clause 4 "Slopes, Cuttings and Embankments". [ABSTRACT FROM AUTHOR]

The second generation of Eurocode 7 aims at covering ground, including both soil and rock. Current practice of ground engineering forms the basis, and the aim is to include rock engineering, improving ease of use, harmonization of regulations, and covering new developments. This paper deals with EN 1997 part 1 addressing the general rules of geotechnical design, connected to EN 1990, the basis of structural and geotechnical design, and parts 2 and 3 of EN 1997. The design process from ground investigation to the verification of limit states is illustrated with a focus on rock engineering. The following topics are dealt with in more detail: Geotechnical Categories: They are now based on Consequence Classes and newly introduced Geotechnical Complexity Classes. A limit state design to be sufficient has to be combined with other checks depending on these classes.Replacement of the Design Approaches of the current Eurocode 7: Ultimate limit states will be verified by a combination of Verification Cases with partial factors on actions and action effects, and sets of partial factors on ground properties and resistances, respectively.Application of numerical methods, where a ULS‐verification with two sets of partial factors is defined.Use of probabilistic methods in design by calculation, especially appropriate in cases where properties of discontinuities govern the design.Practice of the Observational Method, including design variants and regulations about their choice. [ABSTRACT FROM AUTHOR]

Heterogeneous construction waste such as masonry rubble has potential as a raw material for the production of lightweight aggregates similar to expanded clays or even pumice. In the present paper, the suitability of feedstocks with considerable gypsum contents was investigated in a pilot plant. Based on the results, initial technological statements could be made. According to these, energetic advantages can be expected in comparison with lightweight aggregates made from expanded clays. [ABSTRACT FROM AUTHOR]

One trend in the pulp and paper industry is the use of nonwood plants, such as annual plants and grasses. They are intended to substitute trees as a raw material source for pulp. Since the composition and fiber properties differ, they need to be evaluated. In this feasibility study, pulp was extracted from hops, hemp, and miscanthus, yields and fiber properties were investigated and compared with available data for pulp from pine and spruce (Northern Bleached Softwood Kraft). Very high yields of up to 86.6 wt % were found for natural pulping and a low kappa number of 3.5 for miscanthus. Accordingly, almost all the lignin was removed. This confirms the high chemical efficiency of the pulps and underlines the great potential of annual plants and grasses. [ABSTRACT FROM AUTHOR]

Debris flow actions on concrete bridge superstructures Bridge structures in alpine areas are subject to various hazards. These also include debris flows. Debris flows events demonstrably also lead to the destruction of bridges. In order to design bridges for such hazards, information on the impact force of debris flow is necessary. For debris‐flow impacts against piers, extensive miniaturized as well as real size tests are available. So far, no such tests are known for bridge superstructures. In this paper miniaturized debris‐flow impact tests on concrete bridge cross‐sections are presented. Based on the test results, recommendations for the design of concrete bridges in exposed locations are proposed. [ABSTRACT FROM AUTHOR]

Traffic Monitoring on a Highway Bridge – Data collection on local traffic characteristics as a basis for site‐specific traffic load models Developing site‐specific traffic load models for individual bridge structures based on local traffic data represents a potentially effective tool for existing road bridges with remaining calculative deficits when assessed according to current codes (guideline for assessment of existing structures, "Nachrechnungsrichtlinie"). A robust data basis to represent the local traffic characteristics is essential for this purpose. This paper presents investigations carried out during a long‐term monitoring campaign to comprehensively describe the traffic load on a selected bridge structure along Federal Highway A 92 over a period of one year. For the campaign, a measurement unit consisting of a laser scanner and a webcam, and structural monitoring with the application of bridge weigh‐in‐motion (BWIM), are used. Suitable strategies and concepts for collecting, processing, and evaluating all available measurement data enable a comprehensive collection of all parameters relevant for traffic load modeling and thus provide a data basis for detailed and realistic modeling of local traffic characteristics. Initial evaluations of the monitoring data for selected parameters and the comparison with otherwise typical assumptions from the literature in case of missing parameter information show partly significant differences to the extreme traffic characteristics underlying the load models in codes. [ABSTRACT FROM AUTHOR]

How safe are our structures? – Conceptual paper of the DGGT Working Group 2.15 "Reliability‐Based Methods in Geotechnical Engineering" The future Eurocode 7 will explicitly allow the use of reliability‐based methods in geotechnical planning and design. In Germany, there is hardly any experience in the practical application of such methods so far and thus the reservations towards these methods are plenty. The new DGGT Working Group (WG) 2.15 "Reliability‐Based Methods in Geotechnical Engineering" has set itself the goal of providing a practical access to those methods by means of practice‐oriented instructions and recommendations as well as accompanying training and further education courses. The aim is to clarify the possibilities and limitations and, above all, to exploit their potential. This article presents the general principles as well as the future fields of work of the WG 2.15. Starting with the introduction of relevant technical terms, the implementation of reliability‐based methods within the current codes of practice and regulations is shown. Using the life cycle of a geotechnical structure, the uncertainties in geotechnical designs and assessments are described. Subsequently it is outlined, in which situations and to what extend reliability‐based methods can aid engineers, clients and inspectors in verification and decision‐making processes. In the future, WG 2.15 will develop recommendations on individual topics and publish them successively. [ABSTRACT FROM AUTHOR]

Experiences with the application of the needle penetrometer test in marlstone The correct assessment of Unconfined Compressive Strength represents one of the core tasks in the context of the planning and execution of civil engineering, tunneling and geotechnical engineering works. However, in weak and non‐durable rock types, sampling, preservation of the natural water content, sample preparation and finally testing with standard laboratory testing methods, such as the Uniaxial Compressive Strength test, is challenging, if not impossible. As early as 1980, the needle penetrometer was developed in Japan as a field test method for estimating the Unconfined Compressive Strength of such rocks. Although the procedure is presented in an ISRM Suggested Method published in 2014, the use of the needle penetrometer and the needle penetrometer index (NPI) is rather unusual in Germany and Central Europe. The paper resumes the results of a large number of tests carried out in the course the geotechnical investigation of pile drilling works in marlstones of the Upper Cretaceous in the vicinity of Münster/Germany. Based on this experience, the article presents an analysis of the potential area of application and comments on the correlation of testing results and Unconfined Compressive Strength. [ABSTRACT FROM AUTHOR]

Nonwoven bonded pre‐applied waterproofing membranes – bond development and properties Pre‐applied bonded membranes are used as an additional waterproofing measure on waterproof concrete structures and are installed before concrete placement. They achieve a bond to the fresh concrete and often use nonwovens, which must be filled with cement paste during concrete placement. However, little is known about the separation of cement paste from fresh concrete, its properties in the nonwoven, or beneficial nonwoven characteristics. The following paper analyzes the bond of nonwovens in three parts: first, the deformation behavior of the nonwovens during concrete placement is determined using microsections. During concrete placement, the nonwovens are compressed and progressively recover during cement paste filling. As the fresh concrete is placed, filtration processes start. Excess water and a limited amount of fine solids separate into the nonwoven. A filter cake forms on top of the nonwoven and is responsible for a water‐rich cement paste within the nonwoven. Only with the onset of vibration compaction is the filter cake loosened, more solids penetrate the nonwoven, and the water‐solid ratio in the nonwoven is lowered. The bond subsequently develops proportionally to the tensile splitting strength of the concrete. Nonwovens influence the bond strength as they control the separable amount of excess water, which degrades the cement paste strength in the bonding layer. [ABSTRACT FROM AUTHOR]

Increase of technical lifetime of infrastructures based on semi‐probabilistic considerations One of the most important measures in the discussion on improved sustainability in construction is to extend the service life of our structures [1]. Therefore, intensive research is conducted with regard to changing environmental conditions as well as external load effects for structures and new materials and their impact on the production and operation of infrastructures. Already now, according to [2], changes in the kinematics of the degradation mechanisms can be observed. In particular, changing environmental conditions (exposures) can accelerate but also slow down the degradation of materials and structures. These understandings of the degradation processes, but also the improved knowledge of the geometry and effective mechanical building material properties, should be effectively transferred into engineering practice for the assessment of structural reliability and remaining service life [3]. This paper presents how the elements of reliability analysis can be combined with the elements of in‐depth testing and monitoring procedures to periodically evaluate the degradation processes due to changing environmental conditions and new building materials. Subsequently, the remaining service life can be continuously updated with the help of semi‐probabilistic partial safety considerations. [ABSTRACT FROM AUTHOR]

Diagonal Laminated Timber (DLT) – resource efficiency through optimized layer arrangements: determination of stiffness properties and deformation analysis This paper deals with the development of diagonal laminated timber (DLT), a composite timber product consisting of individual layers, which are rotated to each other at a certain angle to increase stiffness properties. Therefore, DLT represents an application‐optimized further development of cross laminated timber (CLT). DLT achieves improved mechanical properties with the same amount of material. [ABSTRACT FROM AUTHOR]

Projects Starting the second tunnel boring machine at the Brenner construction site Sillschlucht‐Pfons / Andrehen der zweiten Tunnelbohrmaschine am Brenner‐Baulos Sillschlucht‐Pfons Contracts for caverns and gallery system for Forbach pumped storage power station awarded / Kavernen und Stollensystem für Pumpspeicherkraftwerk Forbach beauftragt Brenner north approach: gallery construction between Schaftenau and Radfeld / Brenner‐Nordzulauf: Stollenbau zwischen Schaftenau und Radfeld First part of the Fehmarnbelt tunnel concreted / Erster Teil des Fehmarnbelt‐Tunnels betoniert EU funds Brenner Base Tunnel with another 700 million euros / EU fördert Brenner Basistunnel mit weiteren 700 Mio. Euro Four international consortia have been selected for railway equipment of the Fehmarnbelt Tunnel / Vier internationale Konsortien für bahntechnsiche Ausrüstung des Fehmarnbelt‐Tunnel ausgewählt Porr wins a major contract for the SuedLink Elbe crossing / Porr gewinnt Großauftrag für SuedLink Elbquerung Lucerne through station: preliminary project completed / Durchgangsbahnhof Luzern: Vorprojekt abgeschlossen Call for papers – Topics for the next issues of Geomechanics and Tunnelling / Themen für die nächsten Ausgaben der „Geomechanics and Tunnelling" [ABSTRACT FROM AUTHOR]

In fluoropolymers, a large portion or even all of the hydrogen atoms in a polymer chain are replaced by fluorine, which results in a number of special properties such as high chemical and temperature resistance. As a result of this combination of properties, these high‐performance polymers are not replaceable, or only with difficulty, for some applications. The recycling of polymers and the associated closing of material loops is an essential development task for the entire polymer industry. Materials such as fluoropolymers have a special position due to their chemical composition and their low market volume, as they cannot be recycled together with other bulk polymers at the end of their life cycle. This paper discusses different processes in terms of their technical maturity and suitability to allow fluoropolymers to be fully recycled. [ABSTRACT FROM AUTHOR]

Experimental investigation on the effect of static system and load arrangement on the shear resistance of beams with low amounts of shear reinforcement In this paper, an experimental investigation on the shear behaviour of beams with low amounts of shear reinforcement and different static systems is presented. Four simply supported beams under concentrated loads, ten cantilevers and three simulated continuous beams under uniformly distributed loads were tested. The shear reinforcement ratio was varied between 0 (without shear reinforcement) and 2.0 times the minimum shear reinforcement according to EC2. The test results show a significant influence of the static system and the loading type on the crack pattern and ultimate load of the beams tested. While a reinforcement level below the minimum shear reinforcement has almost no influence on the shear resistance of simply supported beams under concentrated loads, a very low shear reinforcement leads to a significant increase in the shear capacity of beams under uniform distributed loads. The crack pattern, however, remains unchanged compared to beams without shear reinforcement where shear failure is characterized by a single critical shear crack. The test results were also compared with design and standard specifications. The comparisons show possible improvement potentials in the currently applied models. [ABSTRACT FROM AUTHOR]

New perspectives on the load bearing behavior of RC‐structures without shear reinforcement The shear behavior of structural members has been an integral part of research in concrete structures for more than 100 years. In recent years, various mechanical shear models have been developed that deliver important insights into the background of shear behavior and are able to provide physical explanations for shear failure in RC members without shear reinforcement. However, these models require further experimental validation. New measurement techniques (e.g. digital image correlation or fiber‐optic strain measurement) play a decisive role in this context, allowing deeper insights into the load‐bearing behavior of reinforced concrete components subjected to shear loads. Based on experimental investigations with modern measurement techniques, software has been developed that performs an automated crack detection based on the finite element method with detailed evaluation of the kinematics and the stresses transferred in the crack. In this paper an overview of different evaluation methods of experimental investigations with modern measurement techniques is given, on the basis of which an in‐depth evaluation of new model approaches can be carried out. [ABSTRACT FROM AUTHOR]

Influence of transverse tensile loads on the compressive strength of carbon reinforced concrete Initial findings on the load‐bearing behaviour of carbon reinforced concrete components under uniaxial compressive stress are available, however multi‐axial stress states are of particular relevance for an application in construction practice. It is known from steel reinforced concrete constructions that transverse tensile stresses lead to a reduction in the compressive strength, although there is still no international agreement on the actual reduction. In this paper we investigate the boundary conditions under which carbon reinforced disc shaped specimens can be tested under combined compressive and tensile loading. This includes the anchoring of the carbon yarns required for the tests in limited space conditions as well as the influence of the loading regime – proportional or sequential – and the manufacturing process – laminated or casted – on the test results. Finally, an outlook on the following investigations is given. [ABSTRACT FROM AUTHOR]

Double‐headed studs as shear and punching reinforcement – Current status and outlook Double‐headed studs have been established for decades as a very effective punching shear reinforcement because these reinforcement elements, which are optimized for shear and punching loads, combine a particularly high anchorage performance with a practicable installation on site. In this paper, an overview of current usability and applicability verifications for double‐headed studs in Germany is given. Afterwards, the currently valid design and construction rules for the use of double‐headed studs as shear reinforcement as well as punching reinforcement are summarized. Finally, the next Eurocode 2 generation 2023+is looked at, with excerpts presenting some significant innovations in the future integration of double‐headed studs into the shear and punching rules. [ABSTRACT FROM AUTHOR]

Methods for digital 3D assessment of the disaster situation: lessons from the 2021 flood The flood event of July 2021 caused heavy structural damage to general building stock and infrastructure in the particularly affected areas of Rhineland‐Palatinate and North Rhine‐Westphalia. In order to cope with the consequences and to prepare for future events, different research projects were initiated. The authors coordinated and interlinked these in the area of situational awareness in the form of topic‐specific workshops. The paper focuses on the collection and preparation of damage data as well as first methodological approaches to conceptually structure the disaster situation from the point of view of the various main actors and to design it efficiently in the time frame. The results are elements of a (still under preparation) tool for rapid situation assessment and support of the emergency services, the justification of measures for temporary building safety and support for reconstruction based on reliable risk scenarios and damage prognosis. Based on and after evaluation of available data and information sources, it is shown how purely technically (flights) and empirically (based on improved damage functions) the creation of situation reports can be qualified and the availability of decision‐relevant information be stored in advance. Conclusions and recommendations from the studies and workshops are summarized from the user's point of view. [ABSTRACT FROM AUTHOR]

Long‐term crack monitoring of prestressed concrete structures by means of distributed fiber‐optic strain sensing In the ceiling area of a connecting subway tunnel in Munich, Germany, fiber‐optic sensor cables were installed for continuous long‐term crack monitoring. According to the measurement concept, continuous monitoring of the total deformations as well as several reference date measurements are planned with regard to the actual crack monitoring of the prestressed concrete construction. The aim of the measurements is the fiber‐optic crack monitoring of a pre‐damaged prestressed concrete structure from the 1970s, which was refurbished in the course of the fiber‐optic installation. The structure is exposed to high traffic loads from road traffic as well as temperature impact. The prestressed concrete structure is a single span slab construction with straight and parabolic tendons. The original ceiling had an increased potential for damage on the underside of the slab (crack pattern) as well as severe damages associated with the existing prestressing steel structure. During the renovation of the prestressed concrete slab, shotcrete with supplementary reinforcement was applied to achieve an announcement behavior in case of tendon failure. The following paper reports on the first results of crack monitoring based on continuous fiber optic measurements along the embedded fiber‐optic sensing cables. The measurements are based on the technology of distributed Brillouin sensing. [ABSTRACT FROM AUTHOR]

Fast‐charging station Leipzig – the floating roof on a computer‐generated endless support For a fast‐charging station at the production site of a sports car manufacturer, a roof was to be developed that would transport the image of the brand in addition to I function as weather protection. The existing technical infrastructure, i. e., power lines that could not be built over and movement and maintenance spaces for the charging columns, only allowed for a few and, above all, irregular support points and support positions. The design process results in a seemingly floating roof whose cladding is modelled on an aerofoil supported on a single endless column. The infinite support Spline, iconographically analogous to an initially simple appearing bent‐up paper clip, ensures both the clamping of the cantilevered roof and the global reinforcement through the spatial support positions and inclinations. The geometry was developed using an evolutionary optimisation algorithm with the most outstanding efficiency while complying with the given geometric restrictions. Within the parametric structural model, in addition to the control and analysis of the static performance, the geometric implementation of the milled circular arcs at the head and foot points was also carried out. The entire process, from the development and variant study to the analysis and documentation to the production, thus took place in a closed digital process chain. Therefore, it was possible to achieve the design goal of contrasting a flat roof and a filigree support structure. [ABSTRACT FROM AUTHOR]

Fire testing of loaded carbon tension members The application of carbon tension members is motivated by extraordinary well fatigue behaviour and high tensile strength of the material. Compared to steel, cross sections can be reduced. Steel tension members used for network arch bridges shall be replaced in perspective. The loadbearing behaviour of carbon tension members in case of fire is still unknown. Therefore, fire tests were performed to investigate the failure mechanisms. Based on the derived test data the comparability to conventional steel tension members was estimated. This paper describes real scale fire testing of mechanically loaded carbon tension members, carried out as a part of the joint research project NeZuCa. The test setup consisted of four carbon tension members with circular cross sections and diameters of 36 mm and 51 mm. In absence of a prescriptive fire scenario for the application case intended in the research project and to ensure comparability, a fire exposure according to standard temperature/time curve was chosen. The elongation of the tension members as well as the temperatures of the specimen and the furnace were recorded. [ABSTRACT FROM AUTHOR]

Influence of the arrangement of the punching shear and composite reinforcement made of L steel plates on the load‐bearing capacity The CLIXS punching shear and composite reinforcement system consists of L steel plates with one or two connected stirrups made of reinforcing steel. It is possible to increase the load‐bearing capacity by more than twice the load‐bearing capacity without punching shear reinforcement. The experimental investigations described in the paper were carried out on square slab cut‐outs with a length of 2.8 m and a thickness of 18 and 25 cm. The load‐bearing capacity as a function of the number of uniform arranged L steel plates was determined based on 17 experiments. For this purpose, test specimen with 6 L steel plates up to 36 L steel plates in the first three perimeters were investigated. In addition, 10 test specimen with different sized areas without L steel plates were tested. The areas without L steel plates were between 25 % and 75 % of the area within the first three perimeters. The use of stirrups with a diameter of 8 mm instead of 6 mm was investigated using two test specimens. [ABSTRACT FROM AUTHOR]

Dynamic train‐bridge compatibility: the reference method as a new form of verification Newly developed rail vehicles must be investigated regarding dynamic bridge compatibility before they are placed in service on the rail network of DB Netz AG. In this context, the dynamic effect on bridges from passing trains (train‐bridge interaction) is evaluated based on dynamic calculation results in the ultimate limit state (ULS) and in the serviceability limit state (SLS) and compared with calculated (previously static) minimum capacities of the infrastructure (resistance). In this paper, a new form of verification is presented. It makes it possible to extend the existing static capacities of the bridges by existing dynamic capacities, which usually allow higher permissible vehicle speeds in the railway network. For this purpose, computational results and database‐supported expert knowledge (fusion) from short‐ and long‐term monitoring of existing vehicles and their impact on the infrastructure are used to declare the bridge stock for these existing vehicles as operationally verified. On this basis, an applicable dynamic capacity for new vehicles can be formulated. The procedure is exemplarily shown for the ICE 3 (existing vehicle) and the new development of the BR 408 series (ICE 3neo). [ABSTRACT FROM AUTHOR]

Projects First tunnel boring machine goes into action at Brenner "Sill Gorge‐Pfons" / Andrehen der ersten Tunnelbohrmaschine am Brenner‐Baulos Sillschlucht‐Pfons Deutsche Bahn starts tunnelling for Wendlingen "big bend" / Deutsche Bahn startet Vortrieb für Große Wendlinger Kurve Renaturalisation of Lake Uri using tunnel spoil / Renaturierung des Urnersees mit Tunnelausbruchmaterial Contract awarded for H53 "Pfons‐Brenner" / Zuschlag für Baulos H53 Pfons‐Brenner erteilt Companies New estimate for total cost of the Brenner Base Tunnel / Neue Schätzung der Gesamtkosten für den Brenner Basistunnel Events 2nd European short course "Grouting Fundamentals & Current Practice" in Munich / Zweiter europäischer Short course "Grouting Fundamentals & Current Practice" in München Call for papers – Topics for the next issues of Geomechanics and Tunnelling / Themen für die nächsten Ausgaben der „Geomechanics and Tunnelling" [ABSTRACT FROM AUTHOR]

The challenge of soil classification – Possibilities and advantages of the cone penetration test Geotechnical reports, which include the classification of the subsoil, represent the basis for project planning and are often essential for awarding construction services. Various standards, such as the ISO 14688‐1 and the Unified Soil Classification System (USCS), are used in practice to characterize the soil based on its particle size distribution and plasticity. In contrast, indirect classifications by means of cone penetration tests are based on soil behaviour type charts. In this paper, classification systems based on the physical properties of soils (ISO 14688‐1, USCS) and in‐situ tests are compared at different test and construction sites. The results indicate that soil behaviour type charts according to Robertson (2009, 2016) and Schneider et al. (2008) are suitable for estimating particle size distributions in alpine deposits, even though a better agreement is reached in fine‐grained soils with the USCS, compared to the ISO 14688‐1. Alternative classifications were elaborated for these soil behavior type charts, leading to an improved estimation of the particle size distribution. Further results illustrate that the estimation of particle size distribution by geotechnical engineers requires great experience in fine‐grained soils and can vary significantly. [ABSTRACT FROM AUTHOR]

Numerical investigations on the stability in the lower failure plane In this paper, three methods for verification the stability in the lower failure plane of an anchored retaining wall are compared: i) conventional methods of structural analysis (with different safety definitions), ii) finite element method with reduction of shear strength, iii) static and kinematic collapse theorem in finite element implementation. For the selected example of a retaining wall with one anchor, the two finite element methods investigated provide similar global safety factors as the methods of structural analysis with a safety definition according to design approach 2 of the Eurocode. With the safety definition according to Kranz, significantly higher safety factors follow. Both finite element methods can be used to determine utilization ratios in the sense of the Eurocode. These ratios are in the example shown are similar to the utilization ratios determined by means of design approach 2, but slightly more conservative. The investigations shown are a further indication that modern numerical methods can be used well in design. [ABSTRACT FROM AUTHOR]

Investigation of an engineering model for the assessment of the seismic behaviour of large mobile equipment For large mobile equipment in seismically active regions, seismic stability is an essential and often decisive design criterion. The seismic behaviour of such large equipment is usually characterised by complex nonlinear types of behaviour (uplift, tilting and rocking), which are difficult to compute and analyse in practice. In this paper, a highly simplified engineering model is presented or developed step by step, which should be able to represent basic features of the typical behaviour of large mobile equipment transverse to the rail under seismic excitation. The typical rocking motion of the equipment, as determined in previous analyses, is to be reflected in the simplified model. The engineering model will be designed in such a way that it is able to reproduce qualitative statements about uplift and rocking or tilting as a function of incisive model parameters and seismic excitation. The dissipation mechanisms of the model are presented and seismic tilting spectra are generated using different approaches. The suitability and applicability of these approaches for assessing uplift and rocking tendencies for large mobile equipment is reviewed using representative series of bucket wheel machines and stackers as examples. In addition, parameters are determined for quantitative application to further large mobile equipment and the delimitation criteria of qualitative and quantitative applicability are compiled. [ABSTRACT FROM AUTHOR]

Material properties of historical steels from exhibition hall 12 in Leipzig at elevated temperatures This paper describes material investigations on historic steel structures. In the course of the reconstruction of the exhibition hall 12 in Leipzig, parts of the original load‐bearing structure are to be restored and integrated into the new building. In order to verify the resistance of the structure, material tests were carried out on the steels and the riveted joints both under ambient temperature and at elevated temperatures. In analogy to the regulations of Eurocode 3, calculation values for the verification were derived from the test results. [ABSTRACT FROM AUTHOR]

Damage equivalence factors for deck slabs of steel railway bridges According to EN 1993‐2, the fatigue verification of railway bridges can be based on internal forces due to the standard load model 71. These internal forces are to be multiplied by a dynamic coefficient Φ2 and a damage equivalence factor λ. In this paper, factors λ1 allowing for the damage effect of traffic on quadrilaterally supported plates with torsionally flexible supports at the longitudinal edges as encountered in single‐track railway‐brides in a span range between 10.0 and 27.5 m are derived for three standard traffic situations. The required damage equivalence factors λ are obtained from the factors λ1, considering the annual traffic volume and the requested service life. [ABSTRACT FROM AUTHOR]

3DWelding – additive fabrication of structural steel elements This paper investigates the possibilities of robotic 3D printing with steel (WAAM – Wire and Arc Additive Manufacturing) in the construction industry. The aim of the project team is to develop a stable and economical manufacturing process for customized steel elements. Thus, the influence of different process parameters such as wire feed rate and travel speed on the weld shape and build‐up rate as well as on the material properties will be explained and a parameter window with stable, verified parameter sets will be defined for each material used. Three different filler metals (G 2Si1, G 3Si1, G 4Si1) are tested in terms of their strength and stiffness, with particular attention paid to the joining area between substrate and welded structure. For this purpose, test methods for testing additively manufactured components, especially for shear capacity, have been newly developed. As a proof of concept, an exemplary application is shown and the load‐bearing capacity of this connection is investigated in different configurations. [ABSTRACT FROM AUTHOR]

Unexpected fatigue cracks at main girders of a railway bridge – strain measurements under service and analyses based on fracture mechanics At a steel railway bridge, erected and taken into service in 1960, fatigue cracks were detected at some transverse stiffener to web connections at the lower flange of the main girder. These findings were surprising, because this specific connection detail was suggested in previous national design standards for fatigue. The paper presents the comprehensive strain measurements under service to show the local stress field at the critical detail within the web plate of the main girder, indicating the well‐known phenomenon of distortion‐induced fatigue, but with unexpectedly high resonance‐like bending stresses in the web. Based on fracture mechanics analyses, with implementation of the measured strain/stress data due to local and global effects at the transverse stiffener connection, as well as the measured material properties (fracture toughness and crack growth parameters) the remaining fatigue life was analysed. The positive results allow an unrestricted train operation in the future. It also turned out, that the mixed‐mode effects must be taken into account and considering only mode I at the crack tip may lead to unsafe results. [ABSTRACT FROM AUTHOR]

Manufacture and erection – TWIST The TWIST shell structure of the CUBE Result House was built from carbon concrete using the wet spraying method. The report from the executing company's perspective provides a detailed description of the technological realization based on the plans submitted for execution. The paper deals with special aspects of production, which result from technology, building materials used, building material properties and general conditions during construction. The experience gained should serve the further development of carbon concrete constructions and shows the need for development to be ready for practice with regard to construction. [ABSTRACT FROM AUTHOR]

Image‐based quality conctrol – part 1: consistency and paste content Today, only very simple empirical test methods are available for quality conctrol of fresh concrete on the construction site or in the production plant. Corrective actions in the case of quality deviations are based on a subjective visual inspection and thus on the experience of the inspector. The standard test method in Europe is the flow table test. The consistency of the concrete is derived from the diameter of the spread out fresh concrete. In order to overcome the deficiencies of this subjective fresh concrete testing, an image‐based method for determining (fresh) concrete properties was developed and validated. In addition to the diameter, extensive information can be derived from the surface properties of fresh conrete. In this paper, the image‐based determination of the consistency and the paste content is explained. The image‐based determination of granulometric properties (part 2) and the homogeneity of fresh concrete (part 3) will be presented in planned follow‐up articles. [ABSTRACT FROM AUTHOR]

Rods glued into cross laminated timber – experiments, numerical simulation and load capacity prediction Timber construction is currently pushing new boundaries in terms of dimensions and architectural possibilities, as shown by the increasing number of high‐rise buildings. This is made possible by high‐performance connections, such as glued‐in rods (GiR, with rods made of steel and fibre reinforced polymers), and wood materials, such as cross‐laminated timber (CLT), which consists of several layers of boards glued flat and crosswise to each other, or glued‐laminated timber (GLT) where all layers are glued together in the same orientation. This paper highlights the current state of the art of GiR glued into CLT and gives an overview of recent experimental and numerical results. The similarities, but also the differences, between GiR glued into CLT and GLT, which result from the different orientation of the individual layers, are shown. Another focus is on the prediction of the connection load‐carrying capacity, for which only very few approaches are currently available. [ABSTRACT FROM AUTHOR]

A shear connector for direction‐independent shear force transmission in TCC slabs Currently used timber‐concrete composite (TCC) slabs carry loads only in one direction, and notches or other shear connectors are used for shear force transmission. As a result, these slabs lack the flexibility and effectiveness as a two‐way spanning, reinforced concrete flat slab. To overcome these limitations, a novel bi‐axial spanning TCC slab is being developed. The investigation of this new system is part of a research project, carried out at the University of Kaiserslautern (TUK) in collaboration with Werner Sobek Frankfurt GmbH & Co. KG (WS Frankfurt). The connection of the two cross‐sections is a key component in such systems. Therefore, developing a shear connector for direction‐independent shear force transmission is an important aspect of this project. In this paper, the results of numerical and experimental investigations of the connection system (cylindrical concrete notch) are presented and discussed. The focus is on the stiffness and load‐bearing capability as well as the structural behaviour. [ABSTRACT FROM AUTHOR]