Abstract： Taking a continuously curved box girder bridge on ramp as example, the coupling vibration response and the impact coefficient of space vehiclebridge of the bridge were analyzed. Considering the influence of bridge damping ratio and bridge deck irregularity, the general software of ANSYS was used to simulate the bridge. The vehicle was simplified to 16degreeoffreedom model. The coupled vibration response MATLAB program of highway curved box girder bridge was compiled by modal synthesis method, and the dynamic response of continuously curved box girder bridge was investigated under multivehicle loading. The results show that the impact coefficient of the vertical deflection of main girder is less affected by the number of transversely loaded vehicles, and the dynamic response of the outer web of the midspan section is the largest. It is suggested that the impact coefficient at the outer web should be used for the design. When the longitudinal vehicle spacing is fixed with the vehicle speed less than 22 m·s-1, the impact coefficient is the maximum under the singlevehicle condition and is decreased significantly with the increasing of the number of vehicle loading at the longitudinal direction. When the vehicle speed is more than 22 m·s-1, the impact coefficient of the main girder under the longitudinal twovehicle and threevehicle conditions fluctuates up and down the impact coefficient curve under the singlevehicle condition. The longitudinal vehicle spacing has little influence on the impact coefficient in the design.
