Seismic Response Analysis of Concrete-Filled Steel Tube Arch Bridge Based on Traveling Wave Effect

On the basis of the motion equations of multi-support excitation and under the prerequisite that the traveling wave effect is taken into account,the finite element software ABAQUS is used to establish the model of the whole bridge of a concrete-filled steel tube(CFST) through arch bridge with inclined arch ribs and inclined hangers and the relevant natural vibration characteristics and seismic response are analyzed.The 2nd to the 4th modes show that the rigidity of the bridge deck is greater than that of the arch ribs.The modes after the 6th mode show that the out-of-plane rigidity of the deck is greater than the in-plane rigidity and in the low-frequency area,the in-plane vibration is dominant.The analysis of the seismic response demonstrates that it is the traveling effect that causes the increase of the structural internal force of the CFST bridge in different degrees,the increasing amplitude of axial force of the arch spring is even greater than that of the bending moment,the amplitude has no direct proportion relation with the peak acceleration.When exceeding the critical wave speed,the amplitude of the arch spring starts to rebound.The critical wave speed is related to the factors of the structural dynamic behavior and seismic wave frequency spectrum and moreover the influences of the traveling wave effect on the displacement of the controlled sections of the arch bridge are complicated.