Research On Safety Evaluation And Control Axle Load Of Large Transportation Of Beam Bridge

With the implementation of national key strategies and development,the level of economic development continues to improve,industrial equipment gradually to large,heavy and super-heavy Development,so that the transport of goods gradually "large","heavy",prompting the rapid development of the bulk transport industry.In recent years,due to vehicle overloading and other reasons,resulting in bridge damage and even bridge collapse accidents frequently,It is of great significance to verify the bridge safety of large transport vehicles.This paper is mainly based on the live load effect comparison method,considering the bridge structure load capacity reduction,the study of the bridge structure load limit state calibration when large transport vehicles go through the bridge,considering the impact coefficient of large transport vehicles over the bridge control axle load.Specific research contents include:(1)This paper summarizes the safety assessment methods of large transport vehicles crossing the bridge in China,and determines the live load effect checking method based on the standard bridge reduction to carry out the rapid safety assessment of large transport vehicles crossing the bridge;The combination formula of vehicle live load effect is determined when large transport vehicles cross the bridge,and the large transport vehicle model in this paper is put forward based on the characteristics of large transport vehicles;(2)Through the establishment of the bridge simplified model,the difference between the bridge simplified model and the original model is compared and analyzed,and the finite element model based on the large transport vehicle crossing the bridge is established.The correctness of the solution program is verified by the comparison between the self-made finite element program and the Midas calculation results;The bridge along the high-speed Handan-Xingtai section in Hebei province is classified statistically,and the safety of large transport vehicles is checked according to the comparison method of live load effect;(3)The finite element model is established based on the vehicle-bridge coupled vibration system,simulate the smoothness of different grades of road,and analyze the change of impact coefficient under different grades of road and different speeds.Combined with the actual situation of large transport vehicles,considering the impact coefficient,the control axle load of large transport vehicles crossing the bridge safely under different axle numbers is obtained by step loading.Analyze the variation of the control axle load for different types and spans of bridges,and propose the axle load standards for large transport vehicles on different routes.