Dynamic Response Analysis Of Column Foundation Bridge Under Vehicle Collision

With the rapid development of transportation, the number of large vehicles increased day by day, the problem of vehicle impacting the bridge becomes more prominent. Vehicle collision caused damage to the bridge, which is an important but unresolved subject that the city traffic engineering must face, so it is the important scientific and technological foundation to solve the vehicle- bridge collision by further studying the inner scientific mechanism of the vehicle-bridge collision and providing the targeted anti-collision design methods and protected technical measures.Taking the T beam and box as an example, which was based on nonlinear finite element program ABAQUS, in this paper, the vehicle-bridge collision process was simulated and analyzed, the dynamic response of the column foundation bridge was obtained ,which was under kinds of random conditions, such as different impact velocity, mass, contact height and contact angle, the failure condition of the main girder ,bearing and pier column were discussed in the respects of stress, displacement and energy. Draw the following conclusions:(1) For concrete T beam bridge, the main feature is, the web and flange local will have a serious punching failure, but the pier column and bearing will be little effected; For concrete girder bridge, which has good body integrity and anti-collision ability, the main feature is the bearing's displacement is too large, and the bottom of pier column will have cracks.(2) The two kinds of bridges will have the same trend under various random conditions. Such as, the greater the speed is, the larger the stress and displacement of main beam, bearing and pier column have, and the more serious damage to the bridge.(3) Under various random conditions, the vehicle's kinetic energy, except a small part will be changed into viscous dissipation energy and friction dissipation energy, most of them would be changed into elastic strain energy and plastic strain energy of system.The vehicle-bridge collision is a complex interaction of dynamic evolution, which has a typical feature of high-speed, high nonlinearity, local damage and overall damage. In this paper, concrete T beam bridge and box girder bridge are simulated and analyzed only from views of the impact force, direction, course and energy distribution, while the other kinds of bridges such as steel-concrete composite bridge structures and steel beam structure has not been throughly analyzed, also the anti-collision ability of bridge and the impact of different vehicle models on the bridge has not been deeply researched yet too; In addition, several problems, such as the high strain rate constitutive materials, the large deformation of the bridge strong material nonlinearity by local damage, strong geometric nonlinearity of large displacement by the overall damage to the bridge are not solved, so the research of Coupled Vehicle-Bridge Collision project still has a long way to go.