Abstract:As one of the most effective means to understand the real mechanical behavior and transmission mechanism of the structure, the bridge structure model test has been widely used in the academic and engineering fields. In this paper, the research progress of bridge model test in 2019 is summarized. The typical model test applications and the key scientific issues based on model test are reviewed from four aspects: static model test, fatigue model test, shaking table model test and hybrid test. In addition, this paper also summarized the new testing technology related to model test.Through the summary of this article, model test is an important method to investigate the safety, durability and suitability of bridge structures which use new design, new technology, and new material. And its also an effective method to evaluate the residual life or bearing capacity.The testing technology related to the development of model test mainly focus on measurement of strain, deflection, accelerated velocity, temperature, defect identification and so on.In the end of this paper, the development of bridge model test and new testing technology is prospected.

Abstract:With the global trend of informationization and intelligence in development of scientific and technological innovation, bridge engineering faces new opportunities for innovation. There is a trend of developing intelligent and high-precision bridges, which may profoundly transform the whole life cycle of bridge design, construction and maintenance. To reveal the progress and trend in this field, this paper reviews related research worldwide in 2019, with regard to bridge informatization, intelligent inspection, high-performance intelligent materials, and intelligent disaster prevention/mitigation, and proposes prospects of future research opportunities. According to the review, BIM technologies can significantly improve the productivity, performance, and integration of construction, maintenance and management of bridges. With the development of 5G technology, digital twinning has been introduced into the field of bridge management and maintenance. Intelligent inspection technologies (e.g. UAV and robots) and intelligent algorithms (e.g. computer vision, big data, and deep learning) continuously enrich bridge monitoring methods and improve the accuracy and efficiency. Development and applications of high-performance intelligent construction materials have provided strong thrusts to the development of intelligent bridges. Development of artificial intelligence (AI) technologies bring new approaches for disaster prevention of structures and transportation. To support national development strategies and ensure safety and durability of bridges, future research should focus on the theme of "bridge informatization and intelligence" to carry out theoretical innovation, technical research and engineering applications.

Abstract:With the development of national economic construction, there are more and more mountain highway and railway bridges, and a large part of them are locate in bad geological areas. Debris flow disasters and the secondary disasters induced by them are one of the major disasters of mountain bridges. The upcoming Sichuan-Tibet railway bridges will be also faced the threat of debris flow. At present, there are relatively few studies reviewed three aspects of the influence of debris flow impacting bridges at home and abroad. In order to promote more in-depth research in this direction, this paper briefly reviews the three aspects of debris flow impacting bridges at home and abroad in the past two years, including research methods, debris flow impact force and bridge disaster prevention.Finally, it was proposed that interdisciplinary joint research should be conducted in the study of debris flow impact bridges. Multiple cases of debris flow damage bridges should be studied. The simplified debris flow impact bridge structure load should be combined with tests and numerical simulations. The focus should be on the effect of large stones on the bridge structure and strengthen research on the impact of debris flow.

Abstract:In order to understand the development trend of the research direction of concrete bridge and its high-performance materials in the past year, and on the basis of summarizing the research contents, metholds and achievements, the follow-up reserch will be carried out better, this paper reviews the recent literatures from three aspects of concrete bridges, high-performance concrete materials and high-performance reinforced materials.Furthermore, the literatures are classified, summarized and commented.The results show that the current research on concrete bridges pays more attention to durability, life cycle design, life prediction and performance degradation in extreme environments.For high-performance concrete materials, more attention has been paid to research of green environmental protection, strength/toughness improvement and self-compaction. The related high-performance reinforced materials have been mainly focused on the FRP bars with higher strength and better durability. Finally, the paper points out shortcomings of the existing research and the work to be done in the future.

Abstract:Bridge wind-engineering is an interdisciplinary that aims to study the aeroelastic stability of long-span bridges, as well as wind-induced vibrations and corresponding countermeasures, and provides theoretical basis, methods and techniques for wind-resistant design of bridges. In recent years, the boom of long-span and super long-span bridges advances the development of bridge wind-engineering, giving rise to a series of achievement in both theoretical,test method and wind vibration control technolagy. Focusing on the main problems in the wind-resistant design of long-span bridges, this paper introduces and reviews the main research progress of bridge wind engineering in field measurement of bridge potential wind characteristics, nonlinear flutter characteristics and calculation theory of long-span bridges, chattering calculation theory of bridges, calculation theory of bridge vortex induced vibration and control technology since 2019.

Abstract:Based on the main analysis methods including the classic mechanics and the finite element method, to establish analytical solutions and numerical solutions of various types of bridges under different situations to explore the mechanical behavior of bridge structures is the category of the bridge structure analysis theories. In recent years, with the emergence of new structural forms such as corrugated steel web box girder bridge, The space analysis theory of box girder and the analysis theory of cable-bearing bridge have made great progress.To meet the requirements of current bridge construction situations and to better serve the practical engineering,through reviewing related research, the present paper reports literatures into separate parts, and mainly expounds some focus issues including shear lag of box girders with corrugated steel webs, extension of traditional box girder spatial analysis theory, central tower effects of multi-tower suspension bridge, ultimate capacity of cable-supported bridges and steel-UHPC composite bridge deck system, and extends to explore shortages of box girder and cable-supported bridge refined analysis theories. It is summarized the engineering applications of the research theory, and corresponding suggestions are made to the future study.

Abstract:It is an important research field of bridge engineering to evaluate the safty and adaptability of existing bridges during the remaining service period and put forward maintenane strategies and reinforcement methods, that to put forward maintenance strategies and reinforcement methods, by using modern testing methods, testing technology, evaluation theory, structural theory, numerical simulation, mathematical statistical prediction and other theoretical methods and technical means comprehensively. Based on the literature of 2019, this paper introduces and summarizes the reliability evaluation method of existing bridges based on time-varying theory, reliability calculation method combined with engineering application, maintenance and reinforcement strategy, seismic performance and seismic reinforcement of reinforced concrete pier columns, new materials, new methods and new equipment of bridge reinforcement, etc., in addition, the research prospect is put forward from the aspects of the understanding of the existing structure performance decay, the development of new theories and methods, and the expansion of new research fields according to the actual needs.

Abstract:Uncoated weathering steel bridges expose to the long-term effect of corrosion during the service, and the main corrosion types that influence its performance are uniform corrosion and pitting corrosion. Pitting corrosion can directly reduce the fatigue strength of steels, and the higher the level of fatigue detail, the more serious the reduction of fatigue strength. Fatigue verification is usually the control index in the design of bridge structure. Thus, the post-corrosion fatigue performance of weathering steel (WS) and high performance steel (HPS) need to be investigated. This study carries out fatigue test on corroded Chinese WS Q345CNH and HPS 70W with a total of 20 specimens. Firstly, the neutral salty spraying dry/wet cyclic corrosion test is carried out for 120 cycles in 35 ℃ according to the ISO code, in which the 5% NaCl solution with pH=6.5 is utilized. Then, the fatigue test results of corroded specimens were compared with those of uncorroded specimens. The result indicates a notable drop in the fatigue strength of corroded WS and HPS.When the guarantee rate is not considered, the fatigue strength of HPS 485W and Q345CNH steel under 2×10⁶ load cycles after corrosion is 27.8% and 26.6% lower than that of the uncorroded specimens, respectively. Considering 95% guarantee rate, when m=3 is adopted, it reduces 34.7% and 50.1%, respectively, and is lower than the FAT 125 requirement. The test also suggests that, the stable rust layers with a certain strength are formed on the surface of both kinds of steel. In addition, the whole fatigue cracks are initiated from the pitting flaws.

Abstract:Research and application of monitoring and control theory and technology in bridge construction process is the basic guarantee of bridge engineering quality, it has become an important content in the field of bridge engineering. Based on the published literature in recent two years, combined with the research and engineering practice carried out by the team, this paper briefly reviews the development of this field. Review and comment on the overall progress are carried out from the development process of control theory of long-span bridge (including cable-stayed bridge and suspension bridge) and special control technology of special structure, that including the construction process control of large bridge structure turning, the longitudinal synchronous jacking control of large beam section, and the control of special mechanical problems in the process of reinforcement of existing structures. Further research hotspots in this field are prospected.

Abstract:With the rapid development of transportation and the development of offshore projects, more and more sea-crossing bridges will be built and developed in the future. However, the marine environment in which the sea-crossing bridge located is extremely complex, it will suffer from the huge threat of storm surge and tsunami and other complex and extreme disasters.In recent years, scholars at home and abroad have carried out related research on the problem of extreme wave (wave-current) forces on the superstructure of sea-crossing bridges. In this paper, the theoretical, numerical and experimental research and progress of the superstructure of sea-crossing bridges under extreme waves (wave-current) are reviewed in recent years. It is pointed out that the wave-current interaction should be considered in the simulation of the real marine environment, and the interaction of the superstructure of sea-crossing bridges and extreme wave (wave-current) is a kind of fluid-solid coupling problem. In the future, it is necessary to consider the dynamic response of the superstructure of sea-crossing bridges in numerical calculations and flume tests, and to study the failure mode and failure mechanism of the sea-crossing bridge under the action of extreme waves (wave-current).

Abstract:The bridge health monitoring system (BHMS)continuously measures and records the structural responses by using a variety of sensors and communication devices in the bridge operation process. The automatic analysis of signal data can be done effectively in the BHMS to fulfill the timely danger warning and safety assessment.So as to protect the normal operation of the structure, prolong the service life of the structure, and guide the management and maintenance decision of the bridge structure.As a new branch of bridge engineering, bridge health monitoring technology has gradually become a hot research field. For the sake of the more efficient application of health monitoring system in bridge engineering, this paper summarizes the current states of several representative BHMS techniques: the decision-making analysis for the BHMS implementation, sensor signal preprocessing, signal de-noising processing, modal parameter identification, finite element model updating, damage identification, condition prediction and assessment. Then, the related researches and applications of these key techniques during 2019 are summarized and discussed.Consequently, it is found that the pattern recognition technology and the machine learning method are more and more widely used in the current research of bridge health monitoring.

Abstract:When a vehicle runs on a bridge, the vehicle and the bridge will be mutually influenced in the dynamic behavior, which is called vehicle-bridge interactions. The vehicle-bridge coupled vibration theory can provide the theoretical basis, analysis method and assessment technique for bridge design, line operation, maintenance and management, and it is of important engineering application value. Many scholars have carried out a lot of relevant researches since the 20th century. At present, China's transportation industry has developed rapidly. Conventional vehicle-bridge interaction dynamics are challenged by the dense transportation network, tight transportation capacity, complicated line conditions, etc. Thus, the related theory and technique are being and further developed. This paper summarizes the progress and advances of the vehicle-bridge interaction field in 2019, including the vehicle-bridge interaction model under track irregularity, vehicle-bridge random vibrations under track irregularity, wind-vehicle-bridge coupled vibrations, earthquake-vehicle-bridge coupled vibrations, and maglev vehicle-bridge coupled vibrations. Furthermore, the research hotspots and prospects are provided. The work is expected to promote more comprehensive and in-depth basis researches.

Abstract:Seismic design of bridges is an important branch in bridge engineering. This paper summarized the achievements and development trends of seismic design of bridges in 2019. The main conclusions are as follows: researches on the seismic response mechanism of traditional reinforced concrete bridge piers are becoming more and more refined, and the evolution and control of local damages have received more attention; For prefabricated pier, in addition to the "equivalent cast-in-place" connection, a variety of new configurations that take into account "load transmission" and "energy dissipation" simultaneously have been explored; Self-centering piers may subject to interface decompression under strong earthquakes, resulting in a rapid decrease in the structural stiffness, which is the key problem limiting its promotion; Isolation and energy dissipation devices are developed to having large capacity, deformability, and good weather resistance. Wherein, the semi-active control reveals satisfactory potential; The soil-structure interaction and pier-water interaction are involved more in seismic research, and the calculation accuracy and efficiency of the novel models have been improved. The seismic research of bridges with multi-physics coupling is of great potential.

Abstract:Steel bridge has outstanding advantages, such as high ratio of strength to weight, large spanning ability, easy to factory manufacturing and assembly construction, which is an important direction of future development in bridge engineering in China. However, due to the effects of multiple factors such as service environment, load conditions, traffic demand, structural system and structural detail design, fatigue is a critical issueand has become a worldwide problem restricting the sustainable development of steel bridge. As a hot research topic of bridge engineering, considerable efforts from the field of steel bridge fatigue have been done. This paper focuses on reviewing the latest research progress in the aspects of fatigue damage evolution, service performance degradation mechanism, fatigue resistance assessment and prediction, fatigue crack monitoring and detection methods, fatigue crack reinforcement and maintenance technology of steel bridge made by the domestic and foreign scholars, and briefly summarizes the research progress in 2019 and research focus of the next stage of the steel bridge. The paper analyzes the challenges of research on the key fatigue problems of steel bridge, and discusses in detail the urgent needs and major problems for further development in the aspects of steel bridge fatigue failure mechanism, the new evaluation theory and method for fatigue resistance, the steel bridge fatigue damage of the intelligent monitoring and detecting, and the key technology for steel bridge fatigue cracking reinforcement.

Abstract:The function of the bridge foundation is to transfer traffic loads to the ground. Thus, the safety of the bridge foundation is essential to the safety of the entire bridge structure. The advances of research and development of bridge foundation engineering are crucial for the development of long-span bridges. In recent years, with the development of long-span bridges crossing wide rivers, deep seas, and poor geological regions, there have been some great progresses in the research on the issues related to the design and construction of bridge foundations in China. In this paper, the research progress and findings in such areas as the foundation scour, the sea wave actions, seismic actions, bridge damage assessment, the design and construction of bridge foundations in the region of poor geological conditions, and the reuse of existing bridge foundations are reviewed and commented. Some major findings in these areas are analyzed and discussed. In the conclusions, the future research trends and some important research issues on bridge foundations, which need to be cared by the bridge engineering community, are identified, to provide researchers and engineers with the up-to-date information on the research ideas that further promote the advancement of the bridge foundation engineering.

Abstract:Steel-concrete composite structure is one of the main structures in the field of civil engineering construction,which can give full play to the properties of concrete and steel, thus leading to a sustainable development direction of the bridge structure.In recent years, with the popularization of the concept of green construction and sustainable construction, the proportion of steel-concrete composite bridges in highway and railway bridges has gradually increased. Consequently, many scholars have carried out scientific research and engineering applications on various aspects of steel-concrete composite structural bridges. In order to promote comprehensive and further basic research on this structure, and to guide the practical application in bridge construction, the latest domestic and foreign researches in 2019 were reviewed and summarized. The researches include the overall mechanical behavior of steel-concrete composite structures, shear connectors of steel-concrete composite structures, steel-UHPC composite structures, concrete-filled steel tube structures and steel-concrete composite structures with corrugated steel webs.Based on the latest research progress above, the future research focuses and directions of steel-concrete composite structure are prospected.

Abstract:Prefabricated structure hasthe advantages of accelerating the construction, saving energy and resource, and mitigating the impact on the environment. Prefabricated structure is a reliable way to realize the industrialization of buildings. In recent years, researchers and design engineers have carried out studies on the prefabricated structure. In the field of bridge engineering, due to the rapid development of prefabricated concrete bridge structures, research on prefabricated concrete bridge structures has increased rapidly, and many new prefabricated concrete bridge structures have been applied in practical engineering. This paper presents state of the art on prefabricated concrete bridges in 2019, in views of prefabricated substructure and prefabricated superstructure to discuss the new technology, new structure and typical engineering applications in this field. From the summary of this paper, it was found that the structure of connection and seismic performance of prefabricated bridge piers are the focuses of the research in this field. It is also a key issue that hinders the construction of prefabricated bridge in high intensity region. In the prefabricated superstructure field, the connection structure between the basic prefabricated components has attracted a lot of researchers' attention. The crack resistance and fatigue performance of the connection structure need to be further improved, aiming to achieve the ‘emulative’ mechanical properties.

Abstract:Fiber-reinforced polymer(FRP) has been widely used in modern bridge engineering in recent years due to the excellent material properties that can adapt to the development needs of modern bridge structures towards large spans, light weight, and durability. In order to promote the development of structural forms and designs in the field of bridges using composite materials, this article reviews the research and application of FRP in bridge engineering in recent years from three levels of FRP material properties, structural components and bridge structures. The design concept of FRP material-structure integration is elaborated in detail, and the relevant research of FRP materials in bridge reinforcements, composite components and bridge structures are summarized and commented.The results show that, the current application of FRP in bridge engineering is still limited in the rehibitation and has great potentials in implementing long-span bridges. It is necessary to improve FRP performance and reduce costs as well as formulate product quality inspection standards. Moreover,systematic codes and engineering applications should be established for design, construction and monitor based on the material-structure integration.

Abstract:Around the world, people pay more and more attention to the planning and protection of cultural heritage, while the systematic research and protection of bridge cultural heritage is still at the early stage. From the enlightenment and countermeasures of the planning and protection of heritage bridge to the concept of bridge cultural heritage, and then to the process and experience of the world heritage bridge and cultural heritage protection and planning, this paper demonstrates its necessity and urgency. On the basis of summarizing the existing research, combined with the actual situation of China, this paper puts forward the exhibition of the planning and protection of heritage bridge. This paper aims to help bridge designers quickly and comprehensively understand the new discipline of the planning and protection of heritage bridge, hoping to integrate the idea of bridge cultural heritage planning and protection into the future bridge work.

Abstract:After more than half a century of development, bridge aesthetics has embarked on a path that combines theory and practice, architecture and structure. Many scientific research departments,design institutes, and universities have made great contributions to the theoretical development and practical application of bridge aesthetics. This article sorts out the domestic and foreign development of bridge aesthetics in recent years to review the development achievements by some aspects such as bridge aesthetics theory and design methods, bridge aesthetics on historical and cultural studies, bridge auxiliary building design and landscape ecological aesthetics, bridge architectural criticism and evaluation, bridge aesthetic design practice and bridge aesthetic education etc. Brief prediction of future research hotspots and development directions are made and the author's suggestions and viewpoints are put forward in the end, hoping to promote bridge aesthetics theory and design practice.

Abstract:When the train passes through a viaduct bridge, the vibration energy is transmitted to the bridge deck and other bridge components through the track structure, which gives rise to bridge vibration. The vibrating bridge radiates noise into the air, which is known as bridge-borne noise. In recent years, with the rapid development of high-speed railway and urban rail transit, the prediction methods, generation mechanisms and control measures of rail transit bridge-borne noise have become hot research topics. In addition, with the wide application of the sound barriers on bridges, the noise reduction performances, vibration and secondary structure-borne noise characteristics of sound barriers have also become hot research directions. In this paper, the research on vibration and noise of rail transit bridges and sound barriers in the past year is reviewed, the current research hotspots are summarized, and the future development trend is forecasted.

Abstract:The impact of the bridge is a key problem that affects the construction and operation of the bridge. Scholars have conducted a large amount of research on it and made positive progress. To promote research on the impact of bridges, the authors review the bridge collision events and the current situation of scientific research in 2019, summarize the current analysis hot spots from three aspects of ship collision, rockfall impact and vehicle collision, look forward to the research trend of bridge collision disaster, prevention and control, and the research trend of bridge impact disaster and prevention and control from the aspects of existing research expansion, new materials, new structures and new theoretical methods, among which the introduction of peridynamic research method will open a new window for the mechanism analysis of bridge collision. Among them, the introduction of peridynamic research method will help to deepen the understanding of the nature of collision, and provide a new path for the analysis of bridge impact problems to break through the bottleneck of traditional thinking.