The travelling wave effect has a significant impact on the seismic performance of long-span bridges. For investigation of the travelling wave impact on the seismic response of simply supported girder bridges, a five-span girder bridge with friction pendulum systems (FPS) was used as a study case. Finite-element analysis was carried out to account for the collision effect of the main girder and the dynamic response of the bridge structure. Effects of the travelling wave of seismic excitations were simulated through the absolute displacement input method. Simulation results show that the effect of travelling waves is more pronounced than those of uniform excitations on the bridge main girder and the bottom of the pier. The collision force between main beams significantly increases when the travelling wave effect was considered, and the collision force needs to be fully considered for the seismic design of large-span simply supported girder bridges. As the wave velocity increases, the beam displacement, the shear force at the pier bottom and the bending moment also increase. The overall response amplitude gradually converges to that of a uniform seismic excitation, whereas the pier top displacement and the inter-girder collision force show a declining or gradually shifting pattern.
Li et al. (Tue,) studied this question.