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This paper introduces a novel nothing-on-road (NOR) bridge weigh-in-motion (BWIM) approach with deep learning (DL) and non-invasive ground-based radar (GBR) time-series data. BWIMs allow site-specific structural health monitoring (SHM) but are usually difficult to attach and maintain. GBR measures the bridge deflection contactless. In this study, GBR and an unmanned aerial vehicle (UAV) monitor a two-span bridge in Germany to gather ground-truth data. Based on the UAV data, we determine vehicle type, lane, locus, speed, axle count, and axle spacing for single-presence vehicle crossings. Since displacement is a global response, using peak detection like conventional strain-based BWIMs is challenging. Therefore, we investigate data-driven machine learning approaches to extract the vehicle configurations directly from the displacement data. Despite a small and imbalanced real-world dataset, the proposed approaches classify, e.g., the axle count for trucks with a balanced accuracy of 76.7% satisfyingly. Additionally, we demonstrate that, for the selected bridge, high-frequency vibrations can coincide with axles crossing the junction between the street and the bridge. We evaluate whether filtering approaches via bandpass filtering or wavelet transform can be exploited for axle count and axle spacing identification. Overall, we can show that GBR is a serious contender for BWIM systems. [ABSTRACT FROM AUTHOR]

How would people distribute risks of autonomous vehicles (AVs) in everyday road traffic? The rich literature on the ethics of autonomous vehicles (AVs) revolves around moral judgments in unavoidable collision scenarios. We argue for extending the debate to driving behaviors in everyday road traffic where ubiquitous ethical questions arise due to the permanent redistribution of risk among road users. This distribution of risks raises ethically relevant questions that cannot be evaded by simple heuristics such as "hitting the brakes." Using an interactive, graphical representation of different traffic situations, we measured participants' preferences on driving maneuvers of AVs in a representative survey in Germany. Our participants' preferences deviated significantly from mere collision avoidance. Interestingly, our participants were willing to take risks themselves for the benefit of other road users, suggesting that the social dilemma of AVs may be mitigated in risky environments. Our research might build a bridge between engineers and philosophers to discuss the ethics of AVs more constructively. [ABSTRACT FROM AUTHOR]

For several years, the use of the BIM method has been mandatory for public new construction and replacement projects of the transport infrastructure in the Federal Republic of Germany. As a result, about 20 use cases (UC) for the application of digital models have been defined. Most of them focus on the planning and execution phase. Despite the importance and long duration of the operational phase, there are isolated definitions for use case for operational phase and therefore underrepresented in the overall context. Moreover, none of the published use cases so far consider the specifics of bridge structures. For this reason, a further definition of specific BIM use cases for the operation of bridge structures is needed. In this article, BIM use cases for the use of digital models of bridge structures in the operation and maintenance phase are defined based on a qualitative empirical study. First, the current state of the art is elaborated by means of a literature analysis. Based on this, a expert interviews are conducted and systematically evaluated. The BIM use cases for operation are derived from the results. In addition, requirements and artifacts are defined. This results in a further specification of the use of BIM models in the operational phase of bridge structures and promotes the digitalization of maintenance management. [ABSTRACT FROM AUTHOR]

Monitoring on road bridges in Germany is rare and mostly designed to deal with existing damages and deficits, as a survey of the Federal Ministry of Digital and Transport in Germany has shown in 2020. Other use cases are monitoring to support structural inspection, monitoring to monitor significant structures, or impact monitoring. The objectives, benefits and examples of the various use cases are described in the present article. Monitoring results are most useful when they are combined with other information about the structure, such as repair measures or damage development, in a common data environment. The Digital Twin is a possibility to merge the existing information und represents the highest expression of digital implementation. The Digital Shadow with an automatic data link from the physical to the digital object and the manual data link from the digital to the physical object represents a preliminary stage of the Digital Twin. The implementation of a Digital Shadow is already taking place at a demonstrator structure of the BASt. The basis for the Digital Shadow is the parametric BIM model. In a selected BIM application, the available information was compiled for this bridge and visualized in a common data environment. [ABSTRACT FROM AUTHOR]

The structural condition of bridges in Germany is often affected by aging and increased traffic loads. However, retrofitting or renewing all bridges is not always feasible due to limited resources. Indirect or drive‐by monitoring of bridges with sensors on passing vehicles has been explored as a cost‐effective and scalable alternative to direct monitoring. In this study, we propose a novel High‐Speed Monitoring (HSM) method for determining natural frequencies, based on accelerometers mounted on train axles, developed for speeds under normal operating conditions. In combination with Bayesian optimisation, a resonance curve can be generated using only a few bridge passages, from which the dominant bending natural frequency of a bridge can be determined with an accuracy comparable to direct monitoring. Measurements on an ICE‐TD passaging bridges travelling at high speeds of up to 200 km/h have shown that the natural frequencies can be determined with the same accuracy as direct measurements. Thus, in this study we were able to show that the method is not only accurate, cost‐effective and scalable, but can also be applied at high speeds without affecting operations. [ABSTRACT FROM AUTHOR]

The digitization of processes and methods has been in the focus of construction industry in recent years. Whereas in the automotive industry predictive maintenance is state of the art, the prediction of the service lifetime for bridges is not standardized due to missing sufficient data to develop and train machine learning algorithms. Structural Health Monitoring (SHM) for bridges is used, e.g., to monitor a local damage trend or a structure's response to external influence. Because of the typical SHM tasks, sensors are often built to be attached temporarily to the structure and to be removed afterwards. For predictive maintenance, there is a demand for data from the beginning of the lifetime. In this paper we show challenges and solutions to implement sensors during construction like the integration in the construction planning, the geo‐localization of the sensors, and durability of the sensors to obtain data from first day of lifetime. All these aspects are shown in a practical example for the newly built Isen bridge in Schwindegg, Germany, where a sensory SHM‐system has been installed to measure the bridge's condition starting from day one of its service lifetime. The results show that with a flexible installation team, the installation does not lead to delay in construction. [ABSTRACT FROM AUTHOR]

Along the long service life of the approximately 65,000 bridges in Germany of more than 50 years, it requires the execution of many meetings under the participation of many different parties. These meetings are still location‐bound and run very manually using analog inventory documentation. For an optimization, further digitization as well as dissolution of the location dependency at the structure, immersive technologies can be used in connection with digital twins of bridge structures. This article presents an approach for a location‐independent meeting at the bridge structure under the integration and possibility of interaction of all actors and linking of the digital and physical world. A digital building model of the bridge serves as the data basis and immersive technologies such as augmented and virtual reality as the output and interaction technology. In the first section, the status quo is elaborated based on a literature review. This is followed by the presentation of the theoretical concept. In the next step, the concept is implemented and validated by using a real bridge demonstrator. Finally, further development possibilities as well as still existing challenges are derived. The result of the article shows a concept and the first feasibility of location‐independent meetings in the maintenance management of a bridge by merging the following elements. [ABSTRACT FROM AUTHOR]

There are about 65,000 bridge structures in the infrastructure network of the Federal Republic of Germany. Due to the long operating phase of bridges, they have an influence on sustainability. To evaluate the sustainability of bridges in the operational phase, digital building models can serve as a consistent and structured database to increase the efficiency and transparency. In this article, an innovative evaluation system for measuring and assessing the sustainability of a bridge structure in the operational phase based on a digital bridge twin is developed. First, the workflow is presented in a process model and the necessary requirements for the digital twin of the bridge structure are defined. In addition, the semi‐automatic sustainability assessment system is described and the linkage via an interoperable interface to the digital twin is designed. The approach is tested and validated using a real demonstrator. The result of the paper shows an approach to use digital twins for a novel and semi‐automatic sustainability assessment in the operation of bridge structures. [ABSTRACT FROM AUTHOR]

Featured Application: The existing literature on bridge fragility curves for floods mainly uses analytical approaches. However, it is crucial to validate these models and to identify failure trends and patterns to detect vulnerabilities. Therefore, fragility curves obtained using data from actual collapses can be employed in CAT (catastrophe) models. Indeed, a gateway to faster recovery from bridge failures can be achieved by transferring the financial risk to insurance providers. Fragility curves allow the association of the hazard intensity to several damage levels, thus enabling the use of damage–loss equations. Floods trigger the majority of expenses caused by natural disasters and are also responsible for more than half of bridge collapses. In this study, empirical fragility curves were generated by referring to actual failures that occurred in the 2021 flood in Germany. To achieve this, a calibrated hydraulic model of the event was used. Data were collected through surveys, damage reports and condition ratings from bridge owners. The database comprises 250 bridges. The analysis revealed recurrent failure mechanisms belonging to two main categories: those induced by scour and those caused by hydraulic forcing. The severity of the damage was primarily dependent on the bridge typology and, subsequently, on the deck's weight. The analysis allowed us to draw conclusions regarding the robustness of certain bridge typologies compared to others for a given failure mechanism. The likelihood of occurrence of the triggering mechanism was also highlighted as a factor to consider alongside the damage probability. This study sheds light on existing vulnerabilities of bridges to river floods, discussing specific areas in which literature data are contradictory. The paper also strengthens the call for a shift towards a probabilistic approach for estimating hydraulic force in bridge design and assessment. [ABSTRACT FROM AUTHOR]

Prestressed concrete bridges built between 1960 and 1990 no longer meet today's requirements due to loads and increasing mileage of higher loads that have increased since the bridges were designed. Prestressed concrete bridges are representative of Germany's existing bridges. In order to deal with the large number of ageing bridges, recalculations and measurements for control as well as bridge monitoring are an important means of support. For both, it is important to find features that are damage-sensitive as well as robust against measurement noise, vehicle parameters (dynamics, geometry, weight, etc.) and environmental influences (temperature, wind, etc.). In this paper, we present features for damage detection based on the influence line, which are investigated with respect to the above requirements by using the analytical solution of the Euler–Bernoulli beam and more complex numerical bridge simulations. In this context, we restrict ourselves to the damage caused by bending stress. The features are calculated on the basis of single vehicle crossings over the bridge for the strain in the longitudinal direction as well as for the deflection of the bridge at different sensor positions. The ratio-based features are compared with raw data and natural frequencies in a classification. Additionally, the sensor positioning is considered. The investigations shows that the ratio-based integrated influence lines are equivalent to or better than the modal parameters, especially when noise and temperature changes are taken into account. [ABSTRACT FROM AUTHOR]

Many road bridges in Germany date back to the 1950s and 1960s. They were planned according to the state of the art at the time and measured for conservative traffic forecasts. However, as a strong economic nation with a steadily growing freight and individual transport, the estimated traffic figures were quickly exceeded. The old bridges with undersized road cross-sections cannot meet today's static and capacitive requirements permanently, which is why the existing structures must give way. Since a replacement-free elimination of a traffic route is usually not an option, almost every dismantling is linked to subsequent replacement. Existing traffic relations must be maintained during the construction period. The client and the responsible administrations must ensure that all legal and factual conditions for the procurement of planning permission are met, and that the construction is carried out safely. The challenges and risks that can arise for the client in this process are presented in this article. [ABSTRACT FROM AUTHOR]

Starting from Germany, the VFT bridge girder technology (prefabricated composite beam) has spread in several European countries in the last decades as further development of the standard steel‐concrete composite solution. Its configuration fits perfectly to integral frame bridges built over existing infrastructure with the scope to minimize the traffic disturbance. In this paper a further development with the focus on cost efficiency in span ranges of 40‐55 m is proposed: the RS‐Overpass technology. The change consists in using standard rolled sections by adapting them into the integral frame bridge configuration, further enhancing the structural efficiency with the benefits of high‐steel strength. The constructive details to achieve the polygonal form have been studied to allow easy fabrication and a maximal clearance height over highway traffic lanes. The RS‐Overpass solution is conceived as the economic option of standard highway overpasses, with the aim of a overall construction cost reduction of 5%. The possibility of weathering steel or hot‐dip galvanization create the unique offer for a maintenance‐free solution. [ABSTRACT FROM AUTHOR]

Bridge abutments made of geosynthetic‐reinforced earth (KBE) – a fast and sensible alternative for the construction of new and replacement bridges The improvement of the infrastructure in the Federal Republic of Germany requires the new construction and expansion of roads and highways with the replacement of bridges and abutments. In this context, alternative construction methods are also being investigated, which should lead to a reduction in building time and costs. One of these new and innovative construction methods is the construction of bridge abutments made of geosynthetic reinforced earth (KBE). In contrast to the bridges currently existing and under construction in Germany, this construction method has not been regulated to date, so that approval in individual cases was required for a pilot project. As part of a pilot project, a geosynthetic‐reinforced earth (KBE) was constructed as abutments for a bridge over the highway. The load‐bearing behavior was checked by an accompanying measurement program and i. a. evaluated with regard to stability and usability. The results allow an outlook on the transferability to comparable construction projects. [ABSTRACT FROM AUTHOR]

Retrofitting of the Karlsruhe‐Maxau Rhine‐bridge with high performance concrete The Karlsruhe‐Maxau Rhine‐bridge is a steel bridge with orthotropic deck that was completed in 1966. Over the course of the years the bridge has been continuously repaired and maintained. Due to the highly increased traffic load and the accompanying fatigue damage, the bridge was recently in indispensable need of repair and retrofitting. The bridge deck was hereby retrofitted with a thin layer of reinforced high performance concrete (HPC), a first in Germany. Furthermore, the HPC layer is only 7 cm thin, with a minimum concrete cover of 2 cm, and is placed with no additional sealing layer. The following article describes the concrete placement and quality assurance concept used for the HPC and reports on the retrofitting operations. The performed fresh and hardened concrete tests on the test and bridge deck's concrete are hereby discussed in detail. In the light of experience gathered, and with strict compliance to the defined quality assurance measures, the high performance concrete can be produced and placed successfully without significant fluctuation in concrete performance. In future, a standard construction procedure is conceivable which, with functional tendering of concrete properties, can enable an efficient and economical retrofitting of orthotropic bridge decks. [ABSTRACT FROM AUTHOR]

Fast‐track construction – motivation, history & concepts Many structures such as bridges, building constructions or industrial facilities are currently being replaced by new ones. Their (scheduled) service life is over. In addition, there is a great demand for living space in growing cities. Both, replacements and new constructions, take place in tight traffic systems that are already largely utilized by freight, goods and passenger traffic. Fast‐track construction – meaning on‐site execution here – is motivated by the goals of minimizing additional impact on the traffic systems and making new structures available for their respective usages at short notice. The quality is maintained. The contribution presents the framework of fast‐track construction as an overview article of the special issue. Included are its motivation in Germany and Europe, its historical context with respect to the construction activity of the last decades or centuries, respectively, including current research approaches and principles that are important for fast‐track construction on‐site. [ABSTRACT FROM AUTHOR]

Roads overpassing highways or speedways are rather a common case, as such bridges occur in average every 2 km of highways in densely populated areas. Due to the high number and similar boundary conditions, the design and realization tends to be standardized and repetitive. The total length ranges mostly between 40 and 55 m, whereas the construction height is a limiting factor since minimum clearance heights must be guaranteed both for safety as well as for driving comfort. Due to these reasons, highway overpasses have been a field of application where steel‐framed composite decks have proven their efficiency for this task. Starting from Germany, the VFT technology (prefabricated composite beam) has spread in several European countries in the last decades as further development of the standard steel‐concrete composite solution. Its configuration fits perfectly to integral frame bridges built over existing infrastructure with the scope to minimize the traffic disturbance. In this paper a further step is proposed: the VFT‐RS technology. The change consists in using standard rolled sections by adapting them into the integral frame bridge configuration, further enhancing the structural efficiency with the benefits of high‐steel strength. The possibility of weathering steel or hot‐dip galvanization create the unique offer of a maintenance‐free solution. [ABSTRACT FROM AUTHOR]

Carbon reinforced concrete – An alternative Method for strengthening concrete bridges; Part 3: Design and first experiences of strengthening concrete superstructures with carbon reinforced concrete – federal highway bridges (A 648) across the river Nidda In 2020 two of three bridges, which are part of the german highway road A 648, were strengthened with carbon reinforced concrete for the first time in Germany. The two superstructures were erected in the 1970s as a pre‐stressed beam. As tendons a so called ‐sigma‐oval‐steel was used, which is sensitive for stress corrosion cracking. According to German guidelines and to exclude a sudden failure, it has to be verified if a damage of the tendons can be seen at the surface of the cross section via cracks along the superstructure. This ‐crack before failure‐ criteria was not fulfilled for the described superstructures. With reference to the relevance of the bridges in the local infrastructure around Frankfurt a. M., a strengthening concept was necessary. Due to that fact, a strengthening with carbon reinforced concrete was identified as an economic and minimal invasive method. The report on that forerunner project is divided into three parts. The first part gives an overview about the bridges and the background on stress corrosion cracking, added with explanations about the planning steps. The second part describes the strengthening with carbon reinforced concrete with a focus on bridges. The following third part goes further into detail, regarding the construction and the design of a carbon reinforced strengthening. [ABSTRACT FROM AUTHOR]

Carbon reinforced concrete – An alternative method for strengthening Concrete Bridges; Part 2: Strengthening of concrete bridges with carbon reinforced concrete – pilot project "federal highway bridges (A 648) across the river Nidda In 2020 two of three bridges, which are part of the german highway road A 648, were strengthened with carbon reinforced concrete for the first time in Germany. The two superstructures were erected in the 1970s as a pre‐stressed beam. As tendons a so called ‐sigma‐oval‐steel was used, which is sensitive for stress corrosion cracking. According to German guidelines and to exclude a sudden failure, it has to be verified if a damage of the tendons can be seen at the surface of the cross section via cracks along the superstructure. This ‐crack before failure‐ criteria was not fulfil for the described superstructures. With reference to the relevance of the bridges in the local infrastructure around Frankfurt a. M., a strengthening concept was necessary. Due to that fact, a strengthening with carbon reinforced concrete was identified as an economic and minimal invasive method. The report on that forerunner project is spread into three parts. The first part gives an overview about the bridges and the background on stress corrosion cracking, added with explanations about the planning steps. The following second part describes the strengthening with carbon reinforced concrete with focus on bridges. The third part goes further into detail, regarding the construction and the design of a carbon reinforced strengthening. [ABSTRACT FROM AUTHOR]

Carbon reinforced concrete – An alternative method for strengthening Concrete Bridges; Part 1: Basics and background information to the pilot project "federal highway bridges (A 648) across the river Nidda" In 2020 two of three bridges, which are part of the german highway road A 648, were strengthened with carbon reinforced concrete for the first time in Germany. The two superstructures were erected in the 1970s as a pre‐stressed beam. As tendons a so called ‐sigma‐oval‐steel was used, which is sensitive for stress corrosion cracking. According to German guidelines and to exclude a sudden failure, it has to be verified if a damage of the tendons can be seen at the surface of the cross section via cracks along the superstructure. This ‐crack before failure‐ criteria was not fulfil for the described superstructures. With reference to the relevance of the bridges in the local infrastructure around Frankfurt a. M., a strengthening concept was necessary. Due to that fact, a strengthening with carbon reinforced concrete was identified as an economic and minimal invasive method. The report on that forerunner project is spread into three parts. The following first part gives an overview about the bridges and the background on stress corrosion cracking, added with explanations about the planning steps. The second part describes the strengthening with carbon reinforced concrete with a focus on bridges. The third part goes further into detail, regarding the construction and the design of a carbon reinforced strengthening for the superstructure. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the potential of detecting and classifying vehicle crossings (events) on bridges with ground-based interferometric radar (GBR) data and machine learning (ML) approaches. The GBR data and image data recorded by a unmanned aerial vehicle, used as ground truth, have been measured during field campaigns at three bridges in Germany non-invasively. Since traffic load of the bridges has taken place during the measurement, we have been able to monitor the bridge dynamics in terms of a vertical displacement. We introduce a methodological approach with three steps including preprocessing of the GBR data, feature extraction and well-chosen ML models. The impact of the preprocessing approaches as well as of the selected features on the classification results is evaluated. In case of the distinction between event and no event, adaptive boosting with low-pass filtering achieves the best classification results. Regarding the distinction between different class types of vehicles, random forest performs best utilising low-pass filtered GBR data. Our results reveal the potential of the GBR data combined with the respective methodological approach to detect and to classify events under real-world conditions. In conclusion, the preliminary results of this paper provide a basis for further improvements such as advanced preprocessing of the GBR data to extracted additional features which then can be used as input for the ML models. [ABSTRACT FROM AUTHOR]

Digital Twins (DTs) provide a promising solution for the maintenance and operation of bridges, thanks to their ability to mirror physical/structural conditions. A bridge DT generally consists of a geometric-semantic model whose creation, however, requires extensive manual effort. This paper presents an automated framework to generate the parametric model of bridges from their segmented point clouds. Following the concept of reverse engineering with parametric modeling, Parametric Prototype Models (PPMs) are proposed as tools to extract parameter values from point clouds. A local and global optimization problem is defined to adjust and assemble PPMs into an integrated model. The proposed approach has been validated by applying it to the point cloud of bridge components as well as point clouds captured from six concrete bridges in Bavaria, Germany. The results show that the proposed approach can generate the parametric model of bridges with a mean absolute error (MAE) of 8.71 cm. • A reverse engineering approach is proposed for the parametric modeling of bridges. • Parametric Prototype Models (PPMs) are introduced to describe bridge point clouds. • Local and global optimization problems are defined to adjust and assemble PPMs. • Metaheuristic optimization algorithms are utilized to derive parameter values. • The method is validated with the point cloud of six bridges in Bavaria, Germany. [ABSTRACT FROM AUTHOR]

China and Germany are countries with a lot of experience in the construction of high-speed railway (HSR) bridges. Standardized design and construction of railway bridges has promoted the initial success of rapidly establishing HSRs in these two countries. Nevertheless, the continued development of HSR bridges brings new challenges to design concepts and engineering technologies. This paper briefly reviews the recent practices of HSR bridges in China and Germany, and summarizes the development of track structures and bridges. The integral design concept of the track-bridge system is presented. Thereinto, continuous ballastless track and integral bridges are introduced. The development trends of HSR bridges—including longer spans, lighter structures and faster train operating speeds—are also discussed. [ABSTRACT FROM AUTHOR]

Bridges are vital components of high-speed rail (HSR) lines for crossing obstacles such as valleys, rivers, and existing highways or railway lines. The main goal of this paper is to provide a review of the development of HSR bridges in Germany. A short summary of the history of high-speed rail lines is given first. Subsequently, the development of HSR bridges, along with emerging design issues and the two relevant German design guidelines, is reviewed. Further, bridge structure types on German HSR lines, such as simply supported bridges, continuous bridges, arch bridges, integral and semi-integral bridges, composite truss bridges and rigid-frame bridges are discussed. The article concludes with a short discussion about the current situation and future trend of HSR bridges. [ABSTRACT FROM AUTHOR]

Currently several major bridges are under construction in Germany, not only due to the construction of new roads and railway connections, but also because of the necessity to demolish and replace older bridges that no longer meet present requirements. Generally, the national infrastructure network is characterised by a relatively high average age of the existing bridges, a progressive increase in traffic volume (particularly with respect to the heavy traffic portion) and also a rise in weight of the individual vehicles and axle loads. In addition, several earlier design approaches for concrete bridges have been modified in modern codes, aiming to increase reserves in bearing capacity and to obtain more robust structures. Hence, an extensive assessment scheme was launched some five years ago, based on the so-called “Nachrechnungsrichtlinie” (guideline for bridge re-analysis and assessment, latest release 04/2015), issued by the Federal Ministry of Transport and Digital Infrastructure, which provides a systematic staged re-analysis approach (four levels of analysis) adapted to the special demands of existing structures. The present paper will firstly give a brief overview of selected new prestressed concrete bridges and related challenges and technical details in design and construction, including the utilisation of innovative materials and/or structural concepts. Subsequently, Germany's assessment strategy for existing bridges will be explained and relevant overall results and findings gained from the re-analysis scheme will be presented and discussed. Finally, current research activities focusing on a more realistic assessment of both actions (e.g. bridge-specific traffic loads) and resistances, i.e. the bearing capacity (particularly regarding the transmission of shear), will be addressed. In view of limited financial resources and the negative consequences induced by civil works in busy traffic infrastructure, it is of utmost importance to only strengthen (or even replace) those bridges where such measures are unavoidable and absolutely necessary. [ABSTRACT FROM AUTHOR]

The article focuses on the reconstruction of the listed arched bridge, also known as Pöppelmann's Stone Bridge, across the Mulde River, Germany. Topics discussed include brief description of the bridge, the damage to the bridge due to summer flooding in 2002, and the design for bridge reconstruction was the result of cooperation with historic buildings and flood prevention authorities.

Betrachtet man die städtebauliche Entwicklung der Stadt Erfurt in der Gründerzeit, so stehen oftmals nur die Architektur und die künstlerische Intension ihrer Schöpfer im Vordergrund. Die bautechnische Leistung der Ingenieure jener Zeit, die auf natur‐ und technikwissenschaftlicher Grundlage planten, entwarfen, konstruierten und berechneten, bleibt im Hintergrund. Dieser Beitrag soll daher die Erfurter Brücken der Gründerzeit und die Ingenieure, die sie erschufen, würdigen. Erfurt – Bridges of the 19th Century If we examine the town planning development of the City of Erfurt during Germany's period of expansion in the 19th century, we often focus solely on the architecture and the artistic intentions of its creators. The structural achievements of the engineers of that time, who planned, designed, built and calculated on a scientific and technical basis, are often ignored. This article therefore aims to pay tribute to the Erfurt bridges of this part of the 19th century and the engineers who created them. [ABSTRACT FROM AUTHOR]

Der Wirtschaftsstandort Deutschland benötigt eine leistungsfähige und zuverlässige Straßeninfrastruktur. Brücken können sehr schnell zu einem Engpass werden, wenn ungeplant Verkehrseinschränkungen bis hin zu Sperrungen vorgenommen werden müssen. In der Vergangenheit wurde dieser möglichen Situation nicht immer ausreichend Rechnung getragen und somit ist es an der Zeit, einer systematischen Brückenerhaltung mehr Bedeutung beizumessen. Die Gründe für den aktuellen Zustand der Brücken sind so vielfältig wie die Brücken selbst. Da spielen Planungs‐ und Ausführungsfehler eine Rolle sowie die Tatsache, dass die Verkehre deutlich stärker zugenommen haben als in allen Prognosen der Vergangenheit vorausgesagt. Da es sich bei Brücken fast immer um Unikate handelt, die sich sehr unterschiedlich verhalten, ist das Spektrum der notwendigen Erfassungs‐ und Bewertungsmöglichkeiten und der daraus resultierenden Erhaltungsmaßnahmen sehr vielfältig. So besteht die Herausforderung in der Zukunft darin, dieser Vielfältigkeit angemessen Rechnung zu tragen, um die Brücken möglichst nachhaltig zu erhalten. Die unterschiedlichen Werkzeuge dafür existieren, werden erarbeitet bzw. fortgeschrieben. Jetzt gilt es, diese Möglichkeiten systematisch einzusehen, damit es mit möglichst geringem Aufwand gelingt, für den gesamten Brückenbestand die geeigneten Erhaltungsmaßnahmen zu planen und umzusetzen und dabei die Nutzung – im Vorfeld und während der Erhaltungsmaßnahmen – möglichst wenig zu beeinträchtigen. Systematic maintenance of Bridges – a multidisciplinary challenge The business location Germany requires an efficient and reliable road infrastructure. Bridges can become a bottleneck when unplanned traffic restrictions to the point of closures can occur. In the past this possible situation wasn't considered sufficiently and thus it is to attach more importance to systematic bridge maintenance. The reasons for the current state of the bridges are as varied as the bridges themselves. Planning and execution errors play a role, but also the fact that traffic has increased significantly more than any forecast of the past have predicted is very important. Bridges are normally unique and therefore they behave very differently. So the spectrum of the necessary collection and assessment options and the resulting maintenance measures are very diverse. Thus, the challenge in the future is to address this diversity appropriately in order to obtain the bridges as sustainable as possible. The different tools exist for it, shall be developed and updated. Now it's time to use these facilities systematically, to find the most suitable maintenance measures for the entire bridge inventory with the least possible effort and the least possible interferences of the traffic before and during the maintenance actions. [ABSTRACT FROM AUTHOR]

Persönliches: 60. Geburtstag von Bernd-Friedrich Bornscheuer. (Von Steffen Eisele, Frank-Ulrich, Drexler, Stephan Krämer, Stuttgart) Nachrichten: 'Beton-Oscar' für Salzburger Brücke. TU Wien feiert Erfolge mit Beton 2014 Freyssinet Medals awarded in Mumbai, India Deutscher Brückenbaupreis 2014 verliehen. Gänsebachtalbrücke in Thüringen und Erba-Steg in Bamberg sind die Preisträger Tagungsbericht zum 9. Hans Lorenz Symposium an der Technischen Universität Berlin. (Von Prof. Dr.-Ing. Christian Moormann, Stuttgart) Gewinner des Wettbewerbs 'Auf IT gebaut' auf der bautec 2014 ausgezeichnet DBV-Heft 24 'Begründung eines reduzierten Zuverlässigkeitsindexes und modifizierter Teilsicherheitsbeiwerte für Stahlbetontragwerke im Bestand' erschienen [ABSTRACT FROM AUTHOR]

Als Alternative zum herkömmlichen Beschichten von vollverschlossenen Brückenseilen wurde in den letzten Jahren das automatische Umwickeln mit Butylkautschukbändern entwickelt [1]. Dieses Verfahren hat vor allem den Vorteil, dass an die Untergrundvorbereitung weniger strenge Anforderungen gestellt werden müssen als beim Beschichten und der Verkehr weitgehend ungestört bleibt. Bisher wurden hiermit die Einzelseile von drei deutschen Schrägseilbrücken geschützt. Erstmals wurde das Verfahren jetzt auch zur Sanierung der Tragkabel einer Hängebrücke in Norwegen angewendet. Dabei mussten Lösungen für die spezifischen Gegebenheiten von Hängebrücken - in engem Abstand verlaufende Seile der Tragkabel sowie Anschluss der Hänger und Kabelsattellager - gefunden werden. Als wesentlicher Vorteil erwies sich die Schnelligkeit des Wickelverfahrens: In nur 25 Tagen konnten, trotz einer witterungsbedingten Ausfallzeit von 6 Tagen, 70 % des Gesamtauftrags fertiggestellt werden. Eine Beschichtung wäre bei den klimatischen Verhältnisse nicht - oder nur mit einer sehr aufwendigen Einhausung - möglich gewesen. Innovative rehabilitation of the main cables of a suspension bridge in Norway. As alternative to the traditional painting of locked coil bridge cables, during the last years the automatic wrapping with butyl rubber tapes has been developed [2]. This procedure has the main advantage, that the preparation of the rope surface needs not to be as accurate as for painting and that the traffic on the bridge remains widely undisturbed. So far it has been applied for the individual cables of three cable stayed bridges in Germany. Recently, the procedure has been applied for the rehabilitation of the main cables of a suspension bridge in Norway. For this, solutions had to be developed for the specific conditions of a suspension bridge like small distance between the ropes of the main cables and the connection of the hangers and cable saddles. The main advantage of the procedure was its speed: in only 25 days 70 % of the total works were finished - in spite of losing six days by adverse climatic conditions. Under these circumstances, a painting of the cables would have been impossible or would have required expensive, water and air tight protective devices. [ABSTRACT FROM AUTHOR]

Nach dem Zweiten Weltkrieg war die Fachwerkbrücke in Westeuropa über drei Jahrzehnte lang quasi von der Bildfläche verschwunden. Erst Mitte der 1980er Jahre wird sie dank zweier Ansätze, die auf verschiedenen technischen Entwicklungen beruhen, wiederentdeckt. In Deutschland findet die Fachwerkbrücke im Verbundbrückenbau im Bereich des Hochgeschwindigkeitseisenbahnbaus erneut Verwendung. In Frankreich erfolgt die Annäherung an die Fachwerkbrücke über die Weiterentwicklung der Betonquerschnitte mit außen liegender Vorspannung und Gewichtseinsparungen in den Tragwerksstegen. Angeregt durch die Veröffentlichung von Artikeln über herausragende Bauten breitet sich das Fachwerk in den 1990er Jahren in ganz Europa aus. Zu Beginn des 21. Jahrhunderts kommt das Raumfachwerk mit hohlem Brückenquerschnitt auf, das die Möglichkeit bietet, den Querschnitt zu begehen bzw. zu befahren, und so die Durchdringung der statischen Konstruktion beim Überqueren der Brücke zu einem Erlebnis zu machen. Das Fachwerk ist zur Überbrückung großer Spannweiten und für Experimente mit neuen Querschnitten bestens geeignet und bietet neue Möglichkeiten hinsichtlich Gestalt und Ausdruck. Revival of trusses in bridges. After Second World War, truss bridges almost disappeared in Western Europe for more than three decades. However, in the mid-eighties they were recovered due to several technical developments that led to a dual approach. On one hand, Germany recovered composite truss decks for high speed railway bridges. Meanwhile, the evolution of post-tensioning concrete sections with exterior prestress and the lightening of the webs, led in France to a new approach of the truss. As a result, the impact of significant realizations expands the use of truss bridges throughout Europe in the nineties. Finally, in the twenty-first century tubular trusses provide an interior passage through the truss section, offering the experience of entering the structure. Truss girders are very suitable for saving large spans, as well as to explore new cross sections types and new formal and expressive possibilities. [ABSTRACT FROM AUTHOR]

In 2003 a group of structural engineers founded a new group within the charitable organisation 'Engineers Without Borders Germany'. Inspired by the work of other non-government organisations, they set off with the goal of applying their engineering knowledge to post-disaster relief work and infrastructure development in countries where it was most needed. Over the past 10 years the group has grown into a team of engineers, architects and students spread across Germany who plan, design and execute bridge projects in developing countries. The initial projects were footbridges built in Rwanda, but the scope has expanded ever since. The group aims at providing sustainable design and construction, which means that locally available materials and construction techniques are to be preferred. Further, the training of local engineers is considered important for providing a lasting infrastructure that can be maintained by the communities themselves. To this end, training workshops have been held and a strong relationship with a local university has been established. This paper describes the challenging work of providing safe yet efficient bridge designs and outlines the execution of some projects. It also describes the history of the group and outlines some of the work undertaken in research and development. [ABSTRACT FROM AUTHOR]

The article presents a study on the application of bolted connections in fibre-reinforced polymers. The researchers conducted tests using standard stainless steel bolts and nuts and proposed load resistance models based on experiments. The researchers also determined a partial safety factor using the statistical methods given in EN 1990 and applied mechanically fastened connections to a GFRP pedestrian bridge built near Schwerin, Germany.

The article provides a history and analysis of the Teufelsgraben aqueduct built in 1890 to bring drinking water to the city of Munich, Germany, by the construction firm of Eugen Dyckerhoff, later known for building bridges. One of the first large construction projects of Germany, in which the building material of pressed cement, or Portland cement, was used, the aqueduct is compared to ones such as the Caserta in Italy, and it is discussed as an example of late 19th century concrete bridge building.

We study the formation of capillary bridges between micrometer-sized glass spheres immersed in a binary liquid mixture using bright field and confocal microscopy. The bridges form upon heating due to the preferential wetting of the hydrophilic glass surface by the water-rich phase. If the system is cooled below the demixing temperature, the bridges disappear within a few seconds by intermolecular diffusion. Thus, this system offers the opportunity to switch the bridges on and off and to tune precisely the bridge volume by altering the temperature in a convenient range. We measure the bridge geometry as a function of the temperature from bright field images and calculate the cohesive force. We discuss the influence of the solvent composition on the bridge formation temperature, the strength of the capillary force, and the bridge volume growth rate. Furthermore, we find that the onset of bridge formation coincides with the water−lutidine bulk coexistence curve. [ABSTRACT FROM AUTHOR]

Abstract: We describe the investigation of two old bridges over inland waterways in Germany under a possible ship impact. Both the numbers of ship impacts against bridges in Germany and the structural description of the bridges have been studied. The investigation is based on probabilistic calculations to take into consideration the uncertainty of a possible impact and the uncertainty of material parameters of the historical bridges. The results for the original bridges and additional strengthening measures are presented in terms of probability of failure and also in terms of risk. [Copyright &y& Elsevier]

In 1928, Paul Katz (an employee of the Technische Hochschule Breslau) at the end of his paper "Die älteste eiserne Straßenbrücke des Europäischcn Kontinents" [I] wrote: "If we have managed to provoke an interest of the mentioned institutions (Technische Hochschule Breslau, German Museum of Technology in München, authorities of the city of Breslau) in preservation of the bridge in Laasan (Lażany), then our task has been fulfilled". Publication [I] mad much later papers [2-6], along with the present paper, stipulate similarly. Metallographic and strength tests made have shown that for construction of the bridge in Lażany unique material structure and architectonic solutions had been applied. The ports of the bridge structure have been made of grey pearlitic cast iron fulfilling all present-day requirements. There are still scarce preserved original ports of the bridge, whose documentation is available. Possibly, this is the last chance to rebuild the object, for example, in the settings of a Wroclaw park, thus maintaining it for posterity. [ABSTRACT FROM AUTHOR]

The article focuses on a controversy related to the demolition of two bridges known as "Blue Wonder" in Leipzig, Germany. People protested against the demolition by sitting on pedestrian over the bridge drinking wine and bear. They were listening to the radio program "Blue Wonder," broadcast by an independent local radio to protest against the demolition of bridges. The demonstration highlights the fact that a greater dynamic space of momentary figure develops in association with material and physical groups. It also shows the impact of such protests on city life.

In Germany, bridges have an average age of 40 years. A bridge consumes between 0.4% and 2% of its construction cost per year over its entire life cycle. This means that up to 80% of the construction cost are additionally needed for operation, inspection, maintenance, and destruction. Current practices rely either on paper-based inspections or on abstract specialist software. Every application in the inspection and maintenance sector uses its own data model for structures, inspections, defects, and maintenance. Due to this, data and properties have to be transferred manually, otherwise a converter is necessary for every data exchange between two applications. To overcome this issue, an adequate model standard for inspections, damage, and maintenance is necessary. Modern 3D models may serve as a single source of truth, which has been suggested in the Building Information Modeling (BIM) concept. Further, these models offer a clear visualization of the built infrastructure, and improve not only the planning and construction phases, but also the operation phase of construction projects. BIM is established mostly in the Architecture, Engineering, and Construction (AEC) sector to plan and construct new buildings. Currently, BIM does not cover the whole life cycle of a building, especially not inspection and maintenance. Creating damage models needs the building model first, because a defect is dependent on the building component, its properties and material. Hence, a building information model is necessary to obtain meaningful conclusions from damage information. This paper analyzes the requirements, which arise from practice, and the research that has been done in modeling damage and related information for bridges. With a look at damage categories and use cases related to inspection and maintenance, scientific literature is discussed and synthesized. Finally, research gaps and needs are identified and discussed. [ABSTRACT FROM AUTHOR]