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Automatic modal identification via automatically interpreting the stabilization diagram provides key technique in bridge structural health monitoring. This paper reviews the progress in the area of automatic modal identification based on interpreting the stabilization diagram. The whole identification process is divided into four steps from establishing the stabilization diagram to removing the outliers in the identification results. The criteria and algorithms used in each step in the existing studies are carefully summarized and classified. Comparisons between typical methods in cleaning and interpreting the stabilization diagram are also conducted. Real structure benchmarks used in the existing studies to validate the proposed automatic modal identification methods are also summarized. Based on the review and comparison, the specific ratio method for cleaning the stabilization diagram, the hierarchical clustering method for interpreting the stabilization diagram and the adjusted boxplot for removing the outliers in the identification results are the most suitable methods for each step. The key point of automatic modal identification based on interpreting the stabilization diagram has also discussed, and it is recommended to pay more attention to cleaning the stabilization diagram. Future study about automatic modal identification under situation with very few sensors deployed should be more concerned. This review aims to help researchers and practitioners in implementing existing automatic modal identification algorithms effectively and developing more suitable and practical methods for civil engineering structures in the future. [ABSTRACT FROM AUTHOR]

Fiber-reinforced polymers (FRPs) are widely utilized in the construction of bridges all over the world and are thought to be a potential alternative to steel reinforcement, particularly in concrete structures exposed to harsh conditions or the effects of electromagnetic fields. Although some FRP bridges have already been put into service and others are still being built, there is ongoing discussion in the civil engineering community over the efficacy of FRPs in substituting steel in vibration-prone bridge parts. This study adopts finite element modeling based on numerical and analytical approaches to investigate the dynamic behavior of the viaduct during maglev train operation when the steel-reinforced girder concrete is replaced by FRP-reinforced girder concrete. In this way, a realistic coupled maglev train–viaduct system is developed and validated by comparative analysis with data from field experiments. Then, an investigation of the viaduct dynamic behavior when the girder is reinforced with polyacrylic nitrile carbon FRP or S-glass FRP reveals that system displacement is governed by viaduct stiffness, whereas acceleration is governed by structure weight. Nonetheless, the dynamic load frequency has a considerable impact on the efficacy of FRP as viaduct concrete reinforcement, which has been demonstrated to be effective at particular train speeds dependent on the structure's natural frequency. [ABSTRACT FROM AUTHOR]

The article focuses on the broader impact of bridge failures on transport networks and regional resilience. Topics include the role of soil-structure interactions in seismic bridge design, the development of new strengthening systems for existing bridges, and the use of analytical methods to assess bridge performance under multiple earthquake events.

At present, in terms of aesthetic realization of landscape bridges in China, it is difficult to integrate the standardization of structural design and the divergence of aesthetic design, to express the connotation of bridge in the context of modern urban culture, and to design complex and special-shaped bridge structures. Aiming at such difficult problems, this research was based on a large number of engineering projects, and integrated the theories of transportation, civil engineering, architecture and other disciplines to conduct multidisciplinary collaborative research. A four-dimensional innovative concept and design method of landscape bridges, based on structural performance, architectural culture, environmental coordination, and diverse experience, were proposed. A technical path was opened up through aesthetics, cultural concepts and engineering realization of landscape bridges. A new idea of structural design with deconstraction-reconstruction as the core was proposed, which solved the structural shaping problem of complex special-shaped bridges in 3D-space. Through the application of Five-Ice-Ring Bridge project for the 2022 Beijing Winter Olympics, although the comprehensive steel consumption was increased by about 11% compared with similar conventional bridges, the design goal of creating an cultural icon was achieved in the landscape design with huge amount of social benefits. [ABSTRACT FROM AUTHOR]

The editorial discusses a themed issue on "Multi-Hazard Effects on Engineering Structures" in the Proceedings of the Institution of Civil Engineers journal. The issue aims to showcase recent research developments in understanding the behavior of structures subjected to multiple hazards, the performance of structural response modification devices, developments in codes and standards, probabilistic multi-hazard structural engineering, and measurement and tracking of condition and performance over the lifespan of structures. The editorial emphasizes the importance of studying and addressing the physical and socioeconomic losses caused by multiple hazards and their impact on society. It also highlights the need for scenario-based and site-specific designs and performance assessment for built infrastructure. [Extracted from the article]

The high environmental impact of bridge construction causes numerous dilemmas in decision making related to the choice of the best material and technological solutions and their consequences in subsequent phases. These decisions adopt from the management condition the successful investment in this type of project. A bridge construction project includes consecutive stages: design, construction, operation/maintenance, and decommissioning. The latter usually involves the demolition of the infrastructure, generating elements that cannot be reused. This waste-generating linear production process must be urgently replaced by closed-loop production, framed within the Circular Economy (CE) philosophy that provides a practical response to the challenges related to sustainable development goals (SDGs). This document performs an analysis of case studies in an attempt to sort out the management challenges related to the construction, operation and decommissioning of bridges. The research is based on a questionnaire carried out among civil engineering project managers and explores the possibility of adapting the principles of the Circular Economy in bridge construction projects, especially in the context of the traceability of construction materials used for the construction. [ABSTRACT FROM AUTHOR]

The chance of the big picture – holistic design, planning and implementation of the A 3 motorway section between Erlangen and Würzburg Highways are – with their numerous structures – not only the elementary basis of our mobile civilization, but also a conspicuous and thus formative component of our built environment and landscape. Some 100 years after the construction of the first intersection‐free roads, the evolved highway network presents itself as a collection of mostly purely functional structures from different decades. The major PPP project "Expansion of the A 3 between the Würzburg/Biebelried and Fürth/Erlangen interchanges" is an almost unique opportunity to renew one of the most heavily trafficked European trunk roads on an approx. 80 km long section according to uniform criteria: Timeless design with harmonious integration into highly variable landscapes, high material efficiency, durability and the best possible structural design of all components. Premature obsolescence due to structural defects, vandalism or short‐lived design must be avoided. In 2015, on the initiative of the client, an intensive, interdisciplinary collaboration with architects, civil engineers and landscape planners began. The result in 2017 was a comprehensive design manual and, building on this, specifications and plans for the design and construction of all bridges and noise barriers for the entire project. 113 bridges will be renewed and more than 45 km of noise protection facilities will be built. A holistic view of the highway section to be upgraded instead of the summation of numerous individual measures of varying quality and appearance, honored with the Polis Award in silver and an award at the German Bridge Construction Prize 2020. [ABSTRACT FROM AUTHOR]

Prestressed concrete box girders with web tendons and unbonded transverse prestressing With the introduction of regulations and guidelines for the design of civil engineering structures (BEM‐Ing) especially for the calculation and design of concrete bridges (part 1, section 2), road bridge construction using prestressed concrete will change. For the first time since 1999 the arrangement of internal tendons in webs of box girders, it is permitted again. However, in order to avoid the shortcomings observed in some road bridges, which result, among other things, from a insufficient compaction of the concrete in the webs, stricter boundary conditions for the use of the bridge tendons in road bridge construction will be anchored in the future, while their possible applications in railway bridge construction will remain unchanged. In addition, it is strongly recommended to design road slabs of large width with transverse prestressing. For the deflection limitation of transversely prestressed road slabs, the maximum prestress force is limited in BEM‐Ing, which can be used to determine the required plate thickness by controlling of the concrete tension stresses. This article provides hints on the design and construction of prestressed concrete box bridges according to the new BEM‐Ing and shows which component dimensions result from the new rules. [ABSTRACT FROM AUTHOR]

• Local splitting of bridge girders due to prestressing needs to be always addressed. • Strategy of comprehensive analysis of bridge global and local response is proposed. • Efficiency of the Concrete Damage Plasticity law is confirmed. • Importance of local analyzes of post-tensioned bridges is strongly emphasized. The cracking of a post-tensioned T-beam superstructure, which was built using the incremental launching method, is analyzed in the paper. The problem is studied in detail, as specific damage was observed in the form of longitudinal cracks, especially in the mid-height zone of the girder at the interface of two assembly sections. The paper is a case study. A detailed inspection is done and non-destructive testing results of the girders are briefly discussed. The attention is especially focused on advanced and comprehensive numerical simulations of the bridge mechanical behavior. Linear and nonlinear static calculations are performed employing the Finite Element Method at global and local levels of precision, enabling deep insight into the bridge response during all the stages of bridge construction and after it is opened to traffic. The crack propagation process in local analyses is described by the application of the Concrete Damage Plasticity law, the parameters of which were carefully chosen. The predicted damage patterns closely resemble those observed at the site. The results reveal, that the girder damage process was initiated when centric prestressing was applied, because vertical reinforcement of the assembly section front-end surface was not designed. However, the damage did not compromise the safety of the bridge. Finally, the repair methods employed are described and also a discussion is presented on how to prevent the occurrence of such cracking. [ABSTRACT FROM AUTHOR]

Fast construction using standardization and prefabrication In the future, construction within existing structures will be the standard construction method in the German road network. In this context, it is all the more important to reduce traffic restrictions as far as possible and to minimize the associated increased risk of accidents, economic consequences (congestion costs) and ecological impacts (environmental pollution). A short construction time combined with high level of quality is therefore desirable in many ways. An important element in this connection is building with standardized and prefabricated components. Due to the large number of regulations, specification drawings and existing rules in the field of bridge construction, in principle, this area of civil engineering is predestined for standardized construction methods. Nevertheless, in contrast to some neighboring countries, the precast construction method has been used less frequently in bridge building in recent decades. The market situation of the past decades allowed builders to design structures as one‐offs and produce them with cast‐in‐place concrete, taking advantage of a seemingly unlimited pool of engineers and skilled workers. The argument was that prefabricated bridges per se are less successful in terms of design. However, with the large number of bridges for which this aspect plays a subordinated role, this should not be decisive. Ultimately, there are many ecological and economic reasons for opening up to the modular construction method as presented below. Even more so, if bridge construction should play its part in a sustainable change in the construction industry. [ABSTRACT FROM AUTHOR]

Welded structures under fatigue loading are widely used in civil engineering. The fatigue strength of components such as welded attachments and butt joints are often determining for the dimensioning of bridges, crane runways or tower constructions. The existing design rules of Eurocode 3, Part 1‐9 are mainly based on experimental data. However, the experimental background of Eurocode 3 Part 1‐9 is partly incomplete. Some fatigue detail classifications are based on numerical modelling and engineering judgement. New findings from experimental research allow a revision of these details, leading to higher fatigue strength classifications in many cases. Firstly an overview of an extensive database for fatigue tests on butt joints and welded attachments is addressed. A method for statistical analysis is presented, which allows the consideration of fatigue tests from different sources by using the design philosophy of Eurocode 3 Part 1‐9 and also meeting the requirements of Eurocode 0. The paper is also going to present some new supplementary experimental investigations on a fatigue detail for transverse end welds of cover plates with blended weld toes, which is traditionally used in German bridge design. Finally a revised and simplified fatigue detail catalogue for welded attachments and butt joints is addressed which is intended as a suggestion for the next generation of Eurocode 3 Part 1‐9. [ABSTRACT FROM AUTHOR]

In recent years, interest in BIM and GIS applications in civil engineering has been growing. For bridge engineering, BIM/GIS applications such as simulation, visualization, and secondary development have been used to assist practitioners in managing bridge construction and decision-making, including selection of bridge location maintenance decisions. In situ 3D modelling of existing bridges with detailed images from UAV camera has allowed engineers to conduct remote condition assessments of bridges and decide on required maintenance actions. Several studies have investigated the applications of BIM/GIS technology on bridge projects. However, there has been limited focus on reviewing the outcomes of these studies to identify the limitations of BIM and GIS applications on bridge projects. Therefore, the aim of this study was to review the research on BIM/GIS technology applications in bridge projects over the last decade. Using a systematic review process, a total of 90 publications that met the inclusion criteria were reviewed in this study. The review identified the state-of-the-art methods of BIM and GIS applications, respectively, at the planning and design, construction, and operation and maintenance phases of bridge projects. However, the findings point to segregated application of BIM and GIS at all phases of bridge projects. The findings of this study will contribute to guiding practitioners in selecting appropriate BIM and GIS technologies for different aspects of bridge projects. [ABSTRACT FROM AUTHOR]

A capstone course is an integral part of Civil Engineering (CE) undergraduate education. It requires graduating students to apply knowledge and skills gained from courses in a CE curriculum in a design that mimics 'real world' projects. The scope and level of detail in senior projects can vary noticeably. This paper presents a senior design project in which a group of five students built a pedestrian timber bridge for a local community and participated in the 2019 National Timber Bridge Design Competition. Valuable lessons were learned from both student and faculty perspectives. [ABSTRACT FROM AUTHOR]

Two examples from practice for shear capacity of textile‐reinforced bridge decks Textile‐reinforced concrete (TRC) for new constructions combines high‐performance textiles with a new generation of high‐strength concretes. Due to the corrosion resistance of the non‐metallic reinforcement, the use of TRC for exterior applications is promising, especially with freeze‐thaw and de‐icing salt exposition. The concrete cover and dead loads can be reduced and the production of slender structural elements as well as thin slabs without additional waterproofing or protective decking becomes possible. During the design of several bridges in Remstal and in Ottenhöfen, theoretical models and experiences from previous research projects were used to apply TRC slabs without shear reinforcement. Accompanying the production and construction works, experimental investigations of shear capacity were carried out for quality control of the execution and for validation of assumptions. The present article shows the application potentials and challenges for the use of TRC in civil engineering structures. [ABSTRACT FROM AUTHOR]

Estimation of basic material consumption in civil engineering is very important in the initial phases of project implementation. Its importance is reflected in the impact of material quantities on forming the prices of individual positions, hence on forming the total cost of construction. The construction companies use the estimate of material quantity, among other things, as a base to make a bid on the market. The precision of the offer, taking into account the overall conditions of the business realization, directly influences the profit that the company can make on a specific project. In the early stages of project implementation, there are not enough available data, especially when it comes to the data needed to estimate material consumption, and therefore, the accuracy of material consumption estimation in the early stages of project realization is smaller. The paper presents the research on the use of artificial intelligence for the estimation of concrete and reinforcement consumption and the selection of optimal models for estimation. The estimation model was developed by using artificial neural networks. The best artificial neural network model showed high accuracy in material consumption estimation expressed as the mean absolute percentage error, 8.56% for concrete consumption estimate and 17.31% for reinforcement consumption estimate. [ABSTRACT FROM AUTHOR]

In this paper, the significance of application-oriented fundamental research on concrete and reinforced concrete structures for progress regarding practical applications to structural design is addressed based on four examples. They were treated in a joint research project of Vienna University of Technology and Tongji University. The first topic refers to sudden heating or cooling of concrete structures, the second one to high-dynamic strength of specimens made of cementitious materials, the third one to structural analysis of segmental tunnel rings used in mechanized tunneling, and the fourth one to serviceability and ultimate limit states of concrete hinges used in integral bridge construction. The first two topics deal with exceptional load cases. Results from the fundamental research call for improvements of state-of-the-art simulation approaches used in civil engineering design. The last two topics refer to reinforced concrete hinges used in mechanized tunneling and integral bridge construction, respectively. Integrative research has led to progress regarding the verification of serviceability and ultimate limit states. In all four examples, results from fundamental research are used to scrutinize state-of-the-art approaches used in practical structural design of civil engineering structures. This allows for identifying interesting directions for the future development of design guidelines and standards. [ABSTRACT FROM AUTHOR]

In areas of civil engineering, the resilient friction base isolator (R-FBI) system has been used due to its enhanced isolation performance under seismic excitations. However, because nonlinear behavior of the R-FBI should be reflected in seismic design, effective stiffness (Keff) of the R-FBI is uniformly applied at both peak ground acceleration (PGA) of 0.08 g and 0.154 g which use a multimodal response spectrum (RS) method analysis. For rational seismic design of bridges, it should be required to evaluate the dynamics of the R-FBI from in-field tests and to improve the seismic design procedure based on the performance level of the bridges. The objective of this study is to evaluate the dynamics of the R-FBI and to suggest the performance-based seismic design method for cable-supported bridges with the R-FBI. From the comparison between the experiments' results and modal shape analyses, the modal shape analyses using primary (Ku) or infinite stiffness (fixed end) showed a great agreement with the experimental results compared to the application of Keff in the shape analysis. Additionally, the RS or nonlinear time history method analyses by the PGA levels should be applied by reflecting the dynamic characteristics of the R-FBI for the reasonable and efficient seismic design. [ABSTRACT FROM AUTHOR]

Girder design for suspension bridges has remained largely unchanged for the past 60 years. However, for future super-long bridges, aiming at record-breaking spans beyond 3 km, the girder weight is a limiting factor. Here we report on a design concept, inspired by computational morphogenesis procedures, demonstrating possible weight savings in excess of 28 percent while maintaining manufacturability. Although morphogenesis procedures are rarely used in civil engineering, often due to complicated designs, we demonstrate that even a crude extraction of the main features of the optimized design, followed by a simple parametric optimization, results in hitherto unseen weight reductions. We expect that further studies of the proposed design, as well as applications to other structures, will lead to even greater weight savings and reductions in carbon footprint in a construction industry, currently responsible for 39 percent of the world's CO2 emissions. Girder design for suspension bridges has remained largely unchanged for the past 60 years. Here, the authors present a design resulting in weight savings in excess of 28% while maintaining manufacturability, thus closing the gap towards super-long suspension bridges. [ABSTRACT FROM AUTHOR]

IABSE Outstanding Structure Award Celebration for the Mukogawa Bridge Report by Akira Wada, National Group On 3 February 2020, the IABSE award celebration for the Mukogawa Bridge, which is a road bridge in Japan, was held. Sixty people attended the celebration, including Prof. Manabu Ito (Former President of IABSE), Prof. Yozo Fujino (Honorary Member of IABSE), Prof. Shunichi Nakamura (Vice-president of IABSE), Mr Toyohito Ikeda (Director-General, Road Bureau, Ministry of Land, Infrastructure, Transport and Tourism), West Nippon Expressway Company Ltd (owner), Sumitomo Mitsui Construction (designer and contractor), and bridge engineers and experts. This bridge is the first structure in the world to combine a butterfly web and an extradosed bridge. [Extracted from the article]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The number of cable-stayed bridges being built worldwide has been increasing owing to the increasing demand for long-span bridges. As the stay-cable is one of critical load-carrying members of cable-stayed bridges, its maintenance has become a significant issue. The stay-cable has an inherently low damping ratio with high flexibility, which makes it vulnerable to vibrations owing to wind, rain, and traffic. Excessive vibration of the stay-cable can cause long-term fatigue problems in the stay-cable as well as the cable-stayed bridge. Therefore, civil engineers are required to carry out maintenance measures on stay-cables as a high priority. For the maintenance of the stay-cables, an automated real-time serviceability assessment system using wireless smart sensors was developed in this study. When the displacement of the cable in the mid-span exceeds either the upper or the lower bound provided in most bridge design codes, it is considered as a serviceability failure. The system developed in this study features embedded on-board processing, including the measurement of acceleration, estimation of displacement from measured acceleration, serviceability assessment, and monitoring through wireless communication. A series of laboratory tests were carried out to verify the performance of the developed system. [ABSTRACT FROM AUTHOR]

Highlights from the article: On 4 May 2019, the Philippine Group of IABSE celebrated IABSE's 90th anniversary by conducting an Information Forum on " I IABSE's Outstanding Structure (OStrA) Awardees and Finalists i ", with highlights on the innovations and significance of each bridge and building structure, with members and non-members. Rey Singh and Wennie Oclarino presented an overview of post-tensioning, post-tensioned flat slabs, transfer plates, post-tensioned mat foundations and prefabricated prefinished volumetric construction (PPVC) technologies to illustrate different technologies and construction schemes for high-rise buildings. In the two days of the Conference, 13 main lectures were given by prominent Brazilian and foreign specialists in the field of construction and design of bridges and other structures. Those members with particular knowledge of the bridges and some of the notable buildings on each side were available to provide commentary for those who wanted to know more about their design and construction, but as so often on these occasions it was the social and professional networking and camaraderie that proved more stimulating for most.

As the construction of long-span bridges such as cable-stayed bridges increases worldwide, maintaining bridge serviceability and operability has become an important issue in civil engineering. The stay cable is a principal component of cable-stayed bridges and is generally lightly damped and intrinsically vulnerable to vibration. Excessive vibrations in stay cables can potentially cause long-term fatigue accumulation and serviceability issues. Previous studies have mainly focused on the mitigation of cable vibration within an acceptable operational level, while little attention has been paid to the quantitative assessment of serviceability enhancement provided by vibration control. This study accordingly proposed and evaluated a serviceability assessment method for stay cables equipped with vibration control. Cable serviceability failure was defined according to the range of acceptable cable responses provided in most bridge design codes. The cable serviceability failure probability was then determined by means of the first-passage problem using VanMarcke's approximation. The proposed approach effectively allows the probability of serviceability failure to be calculated depending on the properties of any installed vibration control method. To demonstrate the proposed method, the stay cables of the Second Jindo Bridge in South Korea were evaluated and the analysis results accurately reflected cable behavior during a known wind event and show that the appropriate selection of vibration control method and properties can effectively reduce the probability of serviceability failure. [ABSTRACT FROM AUTHOR]

Highlights • Features are extracted from raw bridge acceleration data from 8 bridges to provide network training data; no FE models are necessary for training. • Multiple neural network voting ensemble configurations are presented. • Impact detection ranges from 91 −100% while average false positive rates are 0.00–0.75%. Abstract Many critical societal functions depend on uninterrupted service of civil engineering infrastructure. Railroads represent important infrastructure components of the transportation sector and provide both passenger and freight services. Railroad bridges over roadways are susceptible to impacts from overheight vehicles and equipment, which may damage bridge girders or supports and must be investigated after each event. One method of monitoring for vehicle-bridge collisions utilizes accelerometers to monitor for abnormal bridge vibrations corresponding to abnormal activity. Passing trains under normal operating conditions frequently produce significant bridge responses that have similar response characteristics to bridge strikes, but do not need to be investigated. This paper presents an expert system which comprises committees of artificial neural networks trained to interrogate data collected from accelerometers mounted on the bridge, assess the nature of the acceleration signal, and classify the event as either a passing train or a potentially damaging impact. This system is trained using acceleration time histories from accelerometers installed on 8 low-clearance rail bridges; no finite element model simulations were used for network training or data stream creation. The presented system accurately detects and classifies impacts with average impact detection performance ranging from 91–100% with average false positive rates limited to 0.00–0.75%. [ABSTRACT FROM AUTHOR]

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The structural form of a bridge during construction is strongly affects its structural form after completion, with innovative construction processes sometimes leading to innovative bridge designs. It is thus important to consider the construction process during bridge design methods. This approach could be applied not only to new construction but also to replacements, reconstructions, or reinforcements. One of the authors has previously systematized the structural forms of bridges and clarified the principles. This study aims to extend these principles to construction systems. Changes in the structural systems of the construction processes and systematization of the relationship between a completed bridge and construction process in a design are illustrated. Three types of structural systems (suspension, beam, and arch systems) were analysed in terms of material efficiency and time efficiency for corresponding construction states of construction, completed, retrofitted, and retrofitting. Each system exhibited different levels of efficiency at different levels of efficiency at different states of construction. This systematization enables the application of a variety of conventional construction methods in a system. This would be helpful in developing new construction methods and designs for bridges. [ABSTRACT FROM AUTHOR]

Reinforced concrete structures have the potential to be durable and capable of withstanding a variety of adverse environmental conditions. However, failures in the structures do still occur as a result of premature reinforcement corrosion. The maintenance and repair of bridges and buildings for their safety requires effective inspection and monitoring techniques for assessing the reinforcement corrosion. Engineers need better techniques for assessing the condition of the structure when the maintenance or repair is required. These methods are required to identify any possible durability problems within structures before they become serious. This paper reviews all the electrochemical and nondestructive techniques from the point of view of corrosion assessment and their applications to bridges, buildings and other civil engineering structures. [ABSTRACT FROM AUTHOR]

The population of Japan peaked in 2010 and has since entered a depopulation period. On the other hand, there are many bridges that were constructed in the past, especially during the period of high economic growth. Their deteriorating state is becoming increasingly evident. It is expected that maintenance and management costs of the development and maintenance of urban infrastructure for bridges will increase. It is necessary to respond to the ageing of the national land stock. This study verifies urban infrastructure methodology to develop and maintenance using a road network of a municipality whose population actually decreases. This methodology makes use of the basic data held by the municipality such as the population and the length of the road. More specific, the authors propose a methodology for applying the triage to the decision-making processes involving bridges such as road bridges, similar to how it is applied when providing medical care to those with injuries caused by large-scale disasters. The proposed methodology is useful for municipal bridge management strategy and can be applied to other countries around the world that may face decreasing population and/or rising debt in the future. [ABSTRACT FROM AUTHOR]

One of the main volcanic processes affecting road bridges are lahars, which are flows of water and volcanic material running down the slopes of a volcano and river valleys. Several studies have evidenced the effects of other volcanic processes on road infrastructure; however, limited information is available about the effects of lahars on bridges. In this paper, bridge failure models due to lahars are proposed and, based on these, fragility curves are developed. Failure models consider the limit state of pier and abutment overturning, and deck sliding caused by lahars. Existing physical models are used to stochastically characterize lahar loads and overturning momentum on bridges. Monte Carlo simulations are applied to quantify the probability of bridge failure given by different lahar depths. Fragility curves of bridges are finally parameterized by maximum likelihood estimation, assuming a cumulative log-normal distribution. Bridge failure models are empirically evaluated using data on 15 bridges that were affected by lahars in the last 50 years. Developed models suggest that decks fail mainly due to pier and/or abutment overturning, rather than deck-sliding forces. Moreover, it is concluded that bridges with piers are more vulnerable to lahars than bridges without piers. Further research is being conducted to develop an application tool to simulate the effects of expected lahars on exposed bridges of a road network. [ABSTRACT FROM AUTHOR]

This study presents a damage detection approach for the long-term health monitoring of bridge structures. The Bayesian approach comprising both Bayesian regression and Bayesian hypothesis testing is proposed to detect the structural changes in an in-service seven-span steel plate girder bridge with Gerber system. Both temperature and vehicle weight effects are accounted in the analysis. The acceleration responses at four points of the bridge span are utilised in this investigation. The data covering three different time periods are used in the bridge health monitoring (BHM). Regression analyses showed that the autoregressive exogenous model considering both temperature and vehicle weight effects has the best performance. The Bayesian factor is found to be a sensitive damage indicator in the BHM. The Bayesian approach can provide updated information in the real-time monitoring of bridge structures. The information provided from the Bayesian approach is convenient and easy to handle compared to the traditional approaches. The applicability of this approach is also validated in a case study where artificially generated damage data is added to the observation data. [ABSTRACT FROM AUTHOR]