The questions of what kind of individuals university education should cultivate,how to cultivate them,and for whom they are being trained are pressing issues that require immediate solutions.Implementing ideological a...The questions of what kind of individuals university education should cultivate,how to cultivate them,and for whom they are being trained are pressing issues that require immediate solutions.Implementing ideological and political education is a fundamental way to address these challenges.Integrating political education into professional courses is just as important as imparting knowledge,fostering interest,transmitting values,and shaping students’character and spirit.The excavation of ideological and political elements in bridge engineering courses should comprehensively consider the dependent subject of ideological and political elements,the source of cases,the depth of excavation,the trade-offs between courses,the commonality and multifaceted nature of ideological and political elements,as well as the two ways of ideological and political elements integration.Ideological and political elements should be integrated into all stages of classroom lectures,course assignments,final examinations,course design,discipline competitions,school-enterprise cooperation,etc.,so as to achieve the effect of educating people in the whole process.展开更多
Cracking during construction is a common occurrence in modern bridge engineering that can directly impact the overall safety of the bridge.Therefore,it is essential to focus on preventing and controlling cracks.As the...Cracking during construction is a common occurrence in modern bridge engineering that can directly impact the overall safety of the bridge.Therefore,it is essential to focus on preventing and controlling cracks.As the construction technology for bridge engineering has evolved,the internal quality of construction has significantly improved.However,the appearance quality remains a crucial factor that reflects the technical expertise of a construction company.Therefore,minimizing cracks and improving the appearance quality of concrete are critical issues that require the attention of construction units,supervision departments,and construction companies.This article will analyze the causes of cracking and suggest corresponding prevention and treatment methods.展开更多
Engineering surveying is an important course for road and bridge engineering technology majors in higher vocational colleges.With the advancement of science and technology,engineering surveying technology is also cons...Engineering surveying is an important course for road and bridge engineering technology majors in higher vocational colleges.With the advancement of science and technology,engineering surveying technology is also constantly developing,so the theoretical knowledge and professional skills that students need to master are also becoming increasingly complicated.To stimulate the students’interest in learning the course,it is necessary to continuously introduce innovative teaching methods into the course.In this paper,the importance of teaching innovation in engineering surveying courses of road and bridge engineering technology majors in higher vocational colleges and the knowledge system that students need to master are analyzed.Subsequently,innovative strategies are proposed to help improve the students’mastery of engineering surveying.展开更多
This article analyzes the application strategies of shotcrete anchor support technology using a highway bridge-tunnel construction project as an example.The article covers various strategies,including support plan for...This article analyzes the application strategies of shotcrete anchor support technology using a highway bridge-tunnel construction project as an example.The article covers various strategies,including support plan formulation,mortar shotcrete anchor construction,grid steel frame construction,steel mesh construction,and concrete support construction.This analysis aims to provide a guideline for those interested in applying this technology and improving the quality and safety of highway bridges and tunnels construction.展开更多
In order to realize the in-situ evaluation of reinforced concrete bridges subjected to fatigue for a long time or after earthquake, an evaluation method for cumulative damage of concrete structures based on unloading ...In order to realize the in-situ evaluation of reinforced concrete bridges subjected to fatigue for a long time or after earthquake, an evaluation method for cumulative damage of concrete structures based on unloading elastic modulus was proposed. First, according to the concrete stress-strain curve and the statistical relationship between residual strain and cumulative strain, the calculation method of static equivalent strain and residual strain concrete based on unloading elastic modulus and the method for estimating the strength of concrete after damage were proposed. The detailed steps of field test and analysis and the practical damage indicators of residual strain were given. Then, the evaluation method of existing stress and strain of Reinforced Concrete Bridge under dead load and the concept of “equivalent dead load bending moment” were put forward. On this basis, the paper analyzed the root cause of the decrease of bearing capacity of Reinforced Concrete Bridge after fatigue damage, and pointed out that the equivalent strain or residual strain of reinforced concrete increases under the fatigue effect, which led to the decreasing of actual live moment and deformation performance while the ultimate load-carrying capacity remained constant or very little decrease. The evaluation method of structure residual capacity was given, and through comparative analysis of eight T reinforced concrete beams that had been in service for 35 years with the static failure tests, the effectiveness of the method was verified.展开更多
In the maintenance work of highway and bridge engineering structures,the fracture delay of high-strength bolts is a content that needs to be focused on and researched.Based on this,the paper analyzes the fracture dela...In the maintenance work of highway and bridge engineering structures,the fracture delay of high-strength bolts is a content that needs to be focused on and researched.Based on this,the paper analyzes the fracture delay of high-strength bolts in highway bridge maintenance,including an overview of the fundamental research on fracture delay and related specific studies.It is hoped that this study can provide scientific reference for the reasonable maintenance of high-strength bolts,so as to ensure the overall maintenance effect of highway bridge projects.展开更多
This article uses real engineering projects as examples to analyze how static load test technology is applied in testing the bridge-bearing capacity.The analysis covers aspects such as testing section layout,test load...This article uses real engineering projects as examples to analyze how static load test technology is applied in testing the bridge-bearing capacity.The analysis covers aspects such as testing section layout,test load and efficiency coefficient,loading plan,evaluation optimization,test result modification,and result evaluation.The aim is to support the accurate detection and evaluation of bridge-bearing capacity.展开更多
A bridge project is taken as an example to analyze the application of bearing capacity detection and evaluation.This article provides a basic overview of the project,the application of bearing capacity detection techn...A bridge project is taken as an example to analyze the application of bearing capacity detection and evaluation.This article provides a basic overview of the project,the application of bearing capacity detection technology,and the bearing capacity assessment analysis.It is hoped that this analysis can provide a scientific reference for the load-bearing capacity detection and evaluation work in bridge engineering projects,thereby achieving a scientific assessment of the overall load-bearing capacity of the bridge engineering structure.展开更多
This article focuses on bridge testing technologies in highway construction and expansion projects.It provides an overview of the inspection process for bridges in highway reconstruction and expansion projects,the mai...This article focuses on bridge testing technologies in highway construction and expansion projects.It provides an overview of the inspection process for bridges in highway reconstruction and expansion projects,the main inspections,and strategies for improving the quality of inspections.Relevant units should conduct bridge inspections using appearance inspections,special inspections,and bearing capacity assessments in highway reconstruction and expansion projects.To effectively improve testing quality,relevant units should also focus on establishing and improving testing standards,strengthening material testing,and improving the overall quality of the testing personnel.This research aims to enhance the quality of highway reconstruction and expansion projects by supporting the sensible application of bridge inspection technology.展开更多
Effective application of digital integrated management and maintenance systems is essential for successful operation and maintenance management of bridge projects.This article analyzes the application strategy of such...Effective application of digital integrated management and maintenance systems is essential for successful operation and maintenance management of bridge projects.This article analyzes the application strategy of such systems.It provides an overview of comprehensive digital management and maintenance of bridges,an analysis of the basic components of the integrated management and maintenance system,and its application strategies.This study aims to offer guidance for the application of the system and to improve the quality of modern bridge engineering management and maintenance work.展开更多
The theoretical design method of enhanced sensitivity fiber grating (FBG) strain sensors was given, and moreover high qualified strain sensors were developed and fabricated, whose sensing properties were good for pr...The theoretical design method of enhanced sensitivity fiber grating (FBG) strain sensors was given, and moreover high qualified strain sensors were developed and fabricated, whose sensing properties were good for practical applications. The strain sensor with cylindrical shell encapsulation contained three tubular structures, due to the uneven surface structure, in the area of the strain concentration, improving the sensitivity. It could achieve the embedment strain measurement and surface measurement and had the advantages of the easy installation. The good agreement was obtained between the measurements and theoretical simulation results. After each calibration test, twenty-four FBG strain sensors and six FBG temperature compensation sensors have been installed on the undersurface of the box girder of Diaoshuiyan bridge in Yongtaiwen highway. Finally, we built up a long-term structure health system for the highway bridge.展开更多
In this paper,the application strategy of ultrasonic detection technology in the detection of concrete foundation piles is analyzed using a construction project as an example.It includes a basic overview of the projec...In this paper,the application strategy of ultrasonic detection technology in the detection of concrete foundation piles is analyzed using a construction project as an example.It includes a basic overview of the project,an overview of ultrasonic testing technology in bridge concrete pile foundation testing,and an analysis of its practical application in the concrete pile foundation testing of this project.The objective of this analysis is to provide some reference for the application of ultrasonic testing technology and the improvement of the quality of bridge concrete pile foundation testing.展开更多
Bridge engineering is an important part of basic engineering in today’s transportation field,and its quality and performance have a vital impact on the improvement and development of modern transportation engineering...Bridge engineering is an important part of basic engineering in today’s transportation field,and its quality and performance have a vital impact on the improvement and development of modern transportation engineering.With the continuous development of transportation engineering,the maintenance and reinforcement of existing bridges are also being given more emphasis.In order to scientifically evaluate the effectiveness of bridge maintenance and reinforcement,this paper analyzes its detection and evaluation,including the significance,key points,and main methods of detection and evaluation.Therefore,this analysis aim to provide some reference for the maintenance and reinforcement and the quality improvement of bridge engineering.展开更多
Asphalt pavement is currently one of the main components in the construction of roads and bridges.However,from a practical point of view,various quality problems are prone to occur in the surface layer of asphalt pave...Asphalt pavement is currently one of the main components in the construction of roads and bridges.However,from a practical point of view,various quality problems are prone to occur in the surface layer of asphalt pavement,which will lead to the poor overall quality of road and bridge projects.Therefore,it should be applied reasonably.Advanced testing technologies are used to test the mixture quality,compaction,segregation,thickness,and other aspects of the asphalt pavement surface layer,so as to improve the quality of the asphalt pavement surface layer,and then improve the overall quality of road and bridge construction.Therefore,this paper mainly analyzes the technologies for asphalt pavement surface layer testing in road and bridge engineering construction.展开更多
A multi-level evaluation model for the superstructure of a damaged prestressed concrete girder or beam bridge is established, and the evaluation indices of the model as well as the rating standards are defined. A norm...A multi-level evaluation model for the superstructure of a damaged prestressed concrete girder or beam bridge is established, and the evaluation indices of the model as well as the rating standards are defined. A normal relative function about the evaluation indices of each element is developed to calculate the relative degree, and for each element there are no sub-level elements. When evaluating the elements in the sub-item level or the index level of the model, the weights of elements pertain to one adopted element, taking into account their degrees of deterioration. Since the relative degrees and structure evaluation scales on the damage conditions are applied to characterize the superstructure of damaged prestressed concrete girder bridges, this method can evaluate the prestressed structure in detail, and the evaluation results agree with the Code for Maintenance of Highway Bridges and Culvers (JTG Hll--2004 ). Finally, a bridge in Jilin province is taken as an example, using the method developed to evaluate its damage conditions, which gives an effective way for bridge engineering.展开更多
In the history of bridge engineering, demand has always been the primary driving force for development. Driven by the huge demand for construction since China’s reform and opening-up, Chinese bridge has leapt forward...In the history of bridge engineering, demand has always been the primary driving force for development. Driven by the huge demand for construction since China’s reform and opening-up, Chinese bridge has leapt forward both quantitatively and qualitatively in three major stages, by completing the transition from “follower” to “competitor,” and nally to “leader.” A new future is emerging for Chinese bridge engi- neering. As an important part of China’s transportation infrastructure, the bridge engineering industry is facing challenges in this new era on how to support the construction of a new form of transportation. This paper provides a summary of the status of bridge technology in China, based on a basic analysis of stock demand, incremental demand, and management demand. It is our belief that the Chinese bridge engi- neering industry must ful ll three outstanding requirements: construction ef ciency, management effec- tiveness, and long-term service. Intelligent technology based on information technology provides a new opportunity for innovation in bridge engineering. As a result, the development path of bridge engineering needs to be changed. This paper puts forward the idea of developing a third-generation bridge project that is characterized by intelligence, and discusses this project’s implications, development focus, and plan. In this way, this work provides a direction for the improvement of the core competitiveness of China’s bridge engineering industry.展开更多
A strong earthquake occurred in Wenchuan County, Sichuan Province, China, on May 12, 2008. Shortly after the earthquake, the Turner-Fairbank Highway Research Center of the Federal Highway Administration, in partnershi...A strong earthquake occurred in Wenchuan County, Sichuan Province, China, on May 12, 2008. Shortly after the earthquake, the Turner-Fairbank Highway Research Center of the Federal Highway Administration, in partnership with the Research Institute of Highways, the Ministry of Communication of China, led a reconnaissance team to conduct a post-earthquake bridge performance investigation of the transportation system in the earthquake affected areas. The U.S. transportation system reconnaissance team visited the area during July 20 24, 2008. This paper presents the findings and lessons learned by the team.展开更多
To study the stiffness distribution of girder and the method to identify modal parameters of cable-stayed bridge, a simplified dynamical finite element method model named three beams model was established for the gird...To study the stiffness distribution of girder and the method to identify modal parameters of cable-stayed bridge, a simplified dynamical finite element method model named three beams model was established for the girder with double ribs. Based on the simplified model four stiffness formulae were deduced according to Hamilton principle. These formulae reflect well the contribution of the flexural, shearing, free torsion and restricted torsion deformation, respectively. An identification method about modal parameters was put forward by combining method of peak value and power spectral density according to modal test under ambient excitation. The dynamic finite element method analysis and modal test were carried out in a long-span concrete cable-stayed bridge. The results show that the errors of frequencies between theoretical analysis and test results are less than 10% mostly, and the most important modal parameters for cable-stayed bridge are determined to be the longitudinal floating mode, the first vertical flexural mode and the first torsional mode, which demonstrate that the method of stiffness distribution for three beams model is accurate and method to identify modal parameters is effective under ambient excitation modal test.展开更多
The steadily growing traffic load has resulted in lots of bridge collapse events over the past decades, especiallyfor short-to-medium span bridges. This study investigated probabilistic and dynamic traffic load effect...The steadily growing traffic load has resulted in lots of bridge collapse events over the past decades, especiallyfor short-to-medium span bridges. This study investigated probabilistic and dynamic traffic load effects on shortto-medium span bridges using practical heavy traffic data in China. Mathematical formulations for traffic-bridgecoupled vibration and probabilistic extrapolation were derived. A framework for extrapolating probabilistic anddynamic traffic load effect was presented to conduct an efficient and accurate extrapolation. An equivalent dynamicwheel load model was demonstrated to be feasible for short-to-medium span bridges. Numerical studies of twotypes of simply-supported bridges were conducted based on site-specific traffic monitoring data. Numerical resultsshow that the simulated samples and fitting lines follow a curve line in the Gumbel distribution coordinate system. Itcan be assumed that dynamic traffic load effects follow Gaussian distribution and the extreme value follows Gumbeldistribution. The equivalent probabilistic amplification factor is smaller than the individual dynamic amplificationfactor, which might be due to the variability of individual samples. Eurocode 1 is the most conservative specificationon vehicle load models, followed by the BS5400 specification. The D60-2015 specification in China and ASSHTOspecification provide lower conservative traffic load models.展开更多
To study the additional aerodynamic effect on a bridge girder under the action of wind-driven rain, the rainfall similarity considering raindrop impact and surface water is first given. Then, the dynamic characteristi...To study the additional aerodynamic effect on a bridge girder under the action of wind-driven rain, the rainfall similarity considering raindrop impact and surface water is first given. Then, the dynamic characteristics and the process of vortex and flutter generation of the segment models under different rain intensities and angles of attack are tested by considering several typical main girder sections as examples. The test results indicate that the start and end wind speeds,interval length and number of vortex vibrations remain unchanged when it is raining, rainfall will reduce the windinduced vortex response. When test rain intensity is large, the decrease of amplitude is obvious. However, after considering the rain intensity similarity in this study, all of actual maximum rain intensities after conversion approach the domestic extreme rain intensity of approximately 709 mm/h. It can be observed that rainfall has a limited influence on the dynamic characteristics of the structure and vortex vibration response. When the test rain intensity is 120 mm/h, the critical wind speed of the model flutter increases by 20%-30%. However, after considering the rain intensity similarity ratio, the influence of rainfall on the wind-induced flutter instability of the bridge girder may be ignored.展开更多
基金Chongqing Institute of Engineering Ideological and Political Teaching Demonstration Course Construction Project(KC20230010)。
文摘The questions of what kind of individuals university education should cultivate,how to cultivate them,and for whom they are being trained are pressing issues that require immediate solutions.Implementing ideological and political education is a fundamental way to address these challenges.Integrating political education into professional courses is just as important as imparting knowledge,fostering interest,transmitting values,and shaping students’character and spirit.The excavation of ideological and political elements in bridge engineering courses should comprehensively consider the dependent subject of ideological and political elements,the source of cases,the depth of excavation,the trade-offs between courses,the commonality and multifaceted nature of ideological and political elements,as well as the two ways of ideological and political elements integration.Ideological and political elements should be integrated into all stages of classroom lectures,course assignments,final examinations,course design,discipline competitions,school-enterprise cooperation,etc.,so as to achieve the effect of educating people in the whole process.
文摘Cracking during construction is a common occurrence in modern bridge engineering that can directly impact the overall safety of the bridge.Therefore,it is essential to focus on preventing and controlling cracks.As the construction technology for bridge engineering has evolved,the internal quality of construction has significantly improved.However,the appearance quality remains a crucial factor that reflects the technical expertise of a construction company.Therefore,minimizing cracks and improving the appearance quality of concrete are critical issues that require the attention of construction units,supervision departments,and construction companies.This article will analyze the causes of cracking and suggest corresponding prevention and treatment methods.
文摘Engineering surveying is an important course for road and bridge engineering technology majors in higher vocational colleges.With the advancement of science and technology,engineering surveying technology is also constantly developing,so the theoretical knowledge and professional skills that students need to master are also becoming increasingly complicated.To stimulate the students’interest in learning the course,it is necessary to continuously introduce innovative teaching methods into the course.In this paper,the importance of teaching innovation in engineering surveying courses of road and bridge engineering technology majors in higher vocational colleges and the knowledge system that students need to master are analyzed.Subsequently,innovative strategies are proposed to help improve the students’mastery of engineering surveying.
文摘This article analyzes the application strategies of shotcrete anchor support technology using a highway bridge-tunnel construction project as an example.The article covers various strategies,including support plan formulation,mortar shotcrete anchor construction,grid steel frame construction,steel mesh construction,and concrete support construction.This analysis aims to provide a guideline for those interested in applying this technology and improving the quality and safety of highway bridges and tunnels construction.
文摘In order to realize the in-situ evaluation of reinforced concrete bridges subjected to fatigue for a long time or after earthquake, an evaluation method for cumulative damage of concrete structures based on unloading elastic modulus was proposed. First, according to the concrete stress-strain curve and the statistical relationship between residual strain and cumulative strain, the calculation method of static equivalent strain and residual strain concrete based on unloading elastic modulus and the method for estimating the strength of concrete after damage were proposed. The detailed steps of field test and analysis and the practical damage indicators of residual strain were given. Then, the evaluation method of existing stress and strain of Reinforced Concrete Bridge under dead load and the concept of “equivalent dead load bending moment” were put forward. On this basis, the paper analyzed the root cause of the decrease of bearing capacity of Reinforced Concrete Bridge after fatigue damage, and pointed out that the equivalent strain or residual strain of reinforced concrete increases under the fatigue effect, which led to the decreasing of actual live moment and deformation performance while the ultimate load-carrying capacity remained constant or very little decrease. The evaluation method of structure residual capacity was given, and through comparative analysis of eight T reinforced concrete beams that had been in service for 35 years with the static failure tests, the effectiveness of the method was verified.
文摘In the maintenance work of highway and bridge engineering structures,the fracture delay of high-strength bolts is a content that needs to be focused on and researched.Based on this,the paper analyzes the fracture delay of high-strength bolts in highway bridge maintenance,including an overview of the fundamental research on fracture delay and related specific studies.It is hoped that this study can provide scientific reference for the reasonable maintenance of high-strength bolts,so as to ensure the overall maintenance effect of highway bridge projects.
文摘This article uses real engineering projects as examples to analyze how static load test technology is applied in testing the bridge-bearing capacity.The analysis covers aspects such as testing section layout,test load and efficiency coefficient,loading plan,evaluation optimization,test result modification,and result evaluation.The aim is to support the accurate detection and evaluation of bridge-bearing capacity.
文摘A bridge project is taken as an example to analyze the application of bearing capacity detection and evaluation.This article provides a basic overview of the project,the application of bearing capacity detection technology,and the bearing capacity assessment analysis.It is hoped that this analysis can provide a scientific reference for the load-bearing capacity detection and evaluation work in bridge engineering projects,thereby achieving a scientific assessment of the overall load-bearing capacity of the bridge engineering structure.
文摘This article focuses on bridge testing technologies in highway construction and expansion projects.It provides an overview of the inspection process for bridges in highway reconstruction and expansion projects,the main inspections,and strategies for improving the quality of inspections.Relevant units should conduct bridge inspections using appearance inspections,special inspections,and bearing capacity assessments in highway reconstruction and expansion projects.To effectively improve testing quality,relevant units should also focus on establishing and improving testing standards,strengthening material testing,and improving the overall quality of the testing personnel.This research aims to enhance the quality of highway reconstruction and expansion projects by supporting the sensible application of bridge inspection technology.
文摘Effective application of digital integrated management and maintenance systems is essential for successful operation and maintenance management of bridge projects.This article analyzes the application strategy of such systems.It provides an overview of comprehensive digital management and maintenance of bridges,an analysis of the basic components of the integrated management and maintenance system,and its application strategies.This study aims to offer guidance for the application of the system and to improve the quality of modern bridge engineering management and maintenance work.
文摘The theoretical design method of enhanced sensitivity fiber grating (FBG) strain sensors was given, and moreover high qualified strain sensors were developed and fabricated, whose sensing properties were good for practical applications. The strain sensor with cylindrical shell encapsulation contained three tubular structures, due to the uneven surface structure, in the area of the strain concentration, improving the sensitivity. It could achieve the embedment strain measurement and surface measurement and had the advantages of the easy installation. The good agreement was obtained between the measurements and theoretical simulation results. After each calibration test, twenty-four FBG strain sensors and six FBG temperature compensation sensors have been installed on the undersurface of the box girder of Diaoshuiyan bridge in Yongtaiwen highway. Finally, we built up a long-term structure health system for the highway bridge.
文摘In this paper,the application strategy of ultrasonic detection technology in the detection of concrete foundation piles is analyzed using a construction project as an example.It includes a basic overview of the project,an overview of ultrasonic testing technology in bridge concrete pile foundation testing,and an analysis of its practical application in the concrete pile foundation testing of this project.The objective of this analysis is to provide some reference for the application of ultrasonic testing technology and the improvement of the quality of bridge concrete pile foundation testing.
文摘Bridge engineering is an important part of basic engineering in today’s transportation field,and its quality and performance have a vital impact on the improvement and development of modern transportation engineering.With the continuous development of transportation engineering,the maintenance and reinforcement of existing bridges are also being given more emphasis.In order to scientifically evaluate the effectiveness of bridge maintenance and reinforcement,this paper analyzes its detection and evaluation,including the significance,key points,and main methods of detection and evaluation.Therefore,this analysis aim to provide some reference for the maintenance and reinforcement and the quality improvement of bridge engineering.
文摘Asphalt pavement is currently one of the main components in the construction of roads and bridges.However,from a practical point of view,various quality problems are prone to occur in the surface layer of asphalt pavement,which will lead to the poor overall quality of road and bridge projects.Therefore,it should be applied reasonably.Advanced testing technologies are used to test the mixture quality,compaction,segregation,thickness,and other aspects of the asphalt pavement surface layer,so as to improve the quality of the asphalt pavement surface layer,and then improve the overall quality of road and bridge construction.Therefore,this paper mainly analyzes the technologies for asphalt pavement surface layer testing in road and bridge engineering construction.
文摘A multi-level evaluation model for the superstructure of a damaged prestressed concrete girder or beam bridge is established, and the evaluation indices of the model as well as the rating standards are defined. A normal relative function about the evaluation indices of each element is developed to calculate the relative degree, and for each element there are no sub-level elements. When evaluating the elements in the sub-item level or the index level of the model, the weights of elements pertain to one adopted element, taking into account their degrees of deterioration. Since the relative degrees and structure evaluation scales on the damage conditions are applied to characterize the superstructure of damaged prestressed concrete girder bridges, this method can evaluate the prestressed structure in detail, and the evaluation results agree with the Code for Maintenance of Highway Bridges and Culvers (JTG Hll--2004 ). Finally, a bridge in Jilin province is taken as an example, using the method developed to evaluate its damage conditions, which gives an effective way for bridge engineering.
文摘In the history of bridge engineering, demand has always been the primary driving force for development. Driven by the huge demand for construction since China’s reform and opening-up, Chinese bridge has leapt forward both quantitatively and qualitatively in three major stages, by completing the transition from “follower” to “competitor,” and nally to “leader.” A new future is emerging for Chinese bridge engi- neering. As an important part of China’s transportation infrastructure, the bridge engineering industry is facing challenges in this new era on how to support the construction of a new form of transportation. This paper provides a summary of the status of bridge technology in China, based on a basic analysis of stock demand, incremental demand, and management demand. It is our belief that the Chinese bridge engi- neering industry must ful ll three outstanding requirements: construction ef ciency, management effec- tiveness, and long-term service. Intelligent technology based on information technology provides a new opportunity for innovation in bridge engineering. As a result, the development path of bridge engineering needs to be changed. This paper puts forward the idea of developing a third-generation bridge project that is characterized by intelligence, and discusses this project’s implications, development focus, and plan. In this way, this work provides a direction for the improvement of the core competitiveness of China’s bridge engineering industry.
基金Turner-Fairbank Highway Research Center of Federal Highway Administration
文摘A strong earthquake occurred in Wenchuan County, Sichuan Province, China, on May 12, 2008. Shortly after the earthquake, the Turner-Fairbank Highway Research Center of the Federal Highway Administration, in partnership with the Research Institute of Highways, the Ministry of Communication of China, led a reconnaissance team to conduct a post-earthquake bridge performance investigation of the transportation system in the earthquake affected areas. The U.S. transportation system reconnaissance team visited the area during July 20 24, 2008. This paper presents the findings and lessons learned by the team.
基金Project(50608008) supported by the National Natural Science Foundation of Chinaproject(20050536002) supported by the Specialized Research Fund for the Doctoral Program of Higher Education
文摘To study the stiffness distribution of girder and the method to identify modal parameters of cable-stayed bridge, a simplified dynamical finite element method model named three beams model was established for the girder with double ribs. Based on the simplified model four stiffness formulae were deduced according to Hamilton principle. These formulae reflect well the contribution of the flexural, shearing, free torsion and restricted torsion deformation, respectively. An identification method about modal parameters was put forward by combining method of peak value and power spectral density according to modal test under ambient excitation. The dynamic finite element method analysis and modal test were carried out in a long-span concrete cable-stayed bridge. The results show that the errors of frequencies between theoretical analysis and test results are less than 10% mostly, and the most important modal parameters for cable-stayed bridge are determined to be the longitudinal floating mode, the first vertical flexural mode and the first torsional mode, which demonstrate that the method of stiffness distribution for three beams model is accurate and method to identify modal parameters is effective under ambient excitation modal test.
基金The research was supported by the National Science Foundation of China(Grant No.51908068)the support from the Key Laboratory of Bridge Engineering Safety Control by Department of Education(Changsha University of Science&Technology).Industry Key Laboratory of Traffic Infrastructure Security Risk Management in Changsha University of Science and Technology(Grant Nos.19KF03,19KB02)Open Fund of Engineering Research Center of Catastrophic Prophylaxis and Treatment of Road&Traffic Safety of Ministry of Education(Grant No.KFJ190403).
文摘The steadily growing traffic load has resulted in lots of bridge collapse events over the past decades, especiallyfor short-to-medium span bridges. This study investigated probabilistic and dynamic traffic load effects on shortto-medium span bridges using practical heavy traffic data in China. Mathematical formulations for traffic-bridgecoupled vibration and probabilistic extrapolation were derived. A framework for extrapolating probabilistic anddynamic traffic load effect was presented to conduct an efficient and accurate extrapolation. An equivalent dynamicwheel load model was demonstrated to be feasible for short-to-medium span bridges. Numerical studies of twotypes of simply-supported bridges were conducted based on site-specific traffic monitoring data. Numerical resultsshow that the simulated samples and fitting lines follow a curve line in the Gumbel distribution coordinate system. Itcan be assumed that dynamic traffic load effects follow Gaussian distribution and the extreme value follows Gumbeldistribution. The equivalent probabilistic amplification factor is smaller than the individual dynamic amplificationfactor, which might be due to the variability of individual samples. Eurocode 1 is the most conservative specificationon vehicle load models, followed by the BS5400 specification. The D60-2015 specification in China and ASSHTOspecification provide lower conservative traffic load models.
基金Projects(20B062,19B054)supported by Excellent Youth Program of Hunan Education Department,ChinaProject(2019JJ50688)supported by Hunan Provincial Natural Science Foundation of ChinaProject(kq195004)supported by Changsha Science and Technology Bureau Project,China。
文摘To study the additional aerodynamic effect on a bridge girder under the action of wind-driven rain, the rainfall similarity considering raindrop impact and surface water is first given. Then, the dynamic characteristics and the process of vortex and flutter generation of the segment models under different rain intensities and angles of attack are tested by considering several typical main girder sections as examples. The test results indicate that the start and end wind speeds,interval length and number of vortex vibrations remain unchanged when it is raining, rainfall will reduce the windinduced vortex response. When test rain intensity is large, the decrease of amplitude is obvious. However, after considering the rain intensity similarity in this study, all of actual maximum rain intensities after conversion approach the domestic extreme rain intensity of approximately 709 mm/h. It can be observed that rainfall has a limited influence on the dynamic characteristics of the structure and vortex vibration response. When the test rain intensity is 120 mm/h, the critical wind speed of the model flutter increases by 20%-30%. However, after considering the rain intensity similarity ratio, the influence of rainfall on the wind-induced flutter instability of the bridge girder may be ignored.