Performance Simulation,response Characteristic Analysis And Safety Evaluation Of Inclined Girder Bridges Under Custom Transport Vehicle Load

With the rapid and orderly development of China’s economy,the highway transportation system has developed rapidly.Especially the "One Belt And One Road" strategy proposed by the state in 2013,Which has greatly promoted the infrastructure construction,and brought more new challenges to the development of the bulk transportation industry.Due to the needs of country’s major construction and development,the transportation industry of heavy and large equipment continues to expand on small and medium-span bridges.In this regard,it has agreat influence on the service life and bearing capacity of small and medium-span bridges.In order to study the dynamic response characteristics and safe traffic performance of large transport vehicles on small and medium span skew beam Bridges,the stress characteristics and calculation modes of skew beam bridges are firstly analyzed.Secondly,based on the large-sized vehicle-bridge coupling vibration analysis module developed by the research group for largesized transportation vehicles,the dynamic response of a typical small and medium-span diagonal beam bridge under the load of large-sized transportation vehicles is simulated and analyzed.Thirdly,according to the simulation data obtained,the influence of different parameters on the dynamic response of large transport vehicles’ skew beam Bridges is analyzed from the aspect of important characteristic parameters.Based on the reliability theory,the passage method for medium and small span inclined beam Bridges is analyzed and introduced from the aspects of safety and durability.The main works are as follows:(1)Starting from the concept and classification of inclined beam bridges,the stress characteristics and corresponding calculation models are analyzed and explained.(2)Based on the vibration coupling analysis software independently developed by the research group,the motion equation of the eight-axle semi-trailer and the coupling relationship between the skew beam bridge and the wheel are established,and the coupling analysis function of the large-size transport vehicle and the beam skew bridge is realized.(3)According to the established coupling analysis system,the dynamic response of 85 small and medium span skew beam Bridges under the action of five typical large-size vehicles under 425 working conditions are realized.(4)Based on the reliability theory,the passage evaluation and analysis of large transport vehicles are carried out.In terms of the normal limit state,the reliability index and failure probability of the large vehicle skew beam bridge are calculated according to the program developed by monte carlo method and MATLAB.In terms of the bearing capacity limit,the partial coefficient of the load of large transport vehicles is selected according to the failure consequence to calculate the load effect of large transport vehicles crossing the bridge and judge whether it meets the the carrying capacity requirement.