INFLUENCE OF WAVE-TRAVEL EFFECT ON SEISMIC RESPONSE OF LARGE-SPAN CFST ARCH BRIDGE

摘要

This paper completed time-history analysis of seismic response for a large-span CFST (concrete filled steel tube) arch bridge with general structural analysis program ANSYS. The finite element model of the bridge, mass matrix and damp matrix that were applied in the seismic analysis were discussed firstly. Through large-massive method, which has a detailed introduction in this paper, the consideration of wave-travel effect was achieved. After proper adjustment for original El-Centro seismic-wave in according to the seismic design code, seismic time-history response analysis of the CFST arch bridge under frequent seismic action was finished. Then, the influences of wave-travel effect on the seismic response of the bridge were discussed. It is concluded that the influence of wave-travel effect on the seismic response of the structure is complex, which results in increasing in-plane displacement response and varying stress response that depend on the seismic duration and the section location. Furthermore, analysis shows that the support of arch is the weakness part of the structure, to which should be paid more attention during the seismic design.