The dynamic load of the vehicle on the bridge is the main living load of the bridge design, and it is also one of the main reasons for the damage of the bridge. The load of double semi-trailer road train is greater than ordinary trucks, vehicle-bridge coupling vibration under the action of dynamic load on the bridge will cause greater deformation and internal force, so the study on coupling vibration of double semi-trailer road train and bridge, is very important for safety of bridge structure. Based on the Lagrange equation, the dynamic model of 10 axle vehicle with 5 degrees of freedom is established, simply supported beam bridge model is also established. The numerical simulation of bridge deck roughness is carried out. The dynamic model of vehicle-bridge coupling system built by the equilibrium conditions between the vehicle and the bridge displacement coordination condition and force. The dynamic response of vehicle-bridge coupling system is solved numerically. Taking 30 meters simply supported T beam bridge as an example, the influence of vehicle speed, tire stiffness and bridge deck irregularity on the dynamic response of the bridge is analyzed by numerical examples. The results show that in the range of a certain speed, the maximum span of the bridge is changed with the increase of the speed, and it will increase with the increase of velocity in a certain speed range. When the tire stiffness changes in the range of 0.5 times ~2 times, the maximum displacement of the bridge increases with the increase of tire stiffness. As the bridge deck becomes worse, the mid span displacement increases obviously.

CICTP