Seismic Response Analysis Of The Long-Span Arch Bridge Under The Horizontal Multiple-Support Excitation

The arch bridge in our country is one kind of common bridge structural style. As known, the effect of traveling wave is noticeable on seismic response of the long-span arch bridge. Therefore, study on the earthquake resistance performance of arch bridge under the excitation of traveling ground motion has the count for much theory significance and the project practical value. Revolving this topic, this article uses the time history analysis and response spectrum method to analyze the dynamic response of a long-span arch bridge under the traveling seismic wave excitation and the simple support excitation respectively. The main research work is described as follows:(1) Based on the numerical analysis for the seismic responses of single degree of freedom system with different natural frequency, the effects of different seismic excitation models on the dynamic responses of the structure are discussed. Four seismic excitation models are used according to the kinematics and dynamics relationships between seismic displacement and acceleration. The numerical results show that the seismic excitation model has important influence on the seismic responses of the structure. It needs to pay more attention for using the seismic displacement model in the dynamic analysis of structure.(2) Using the finite element procedure, the dynamic response mechanism of Wanxian Yangtze River Bridge under the excitation of horizontal harmonic traveling wave with different frequency is researched. The results have indicated that, the traveling wave excitation has the very tremendous influence to the dynamic response of long-span arch bridge. Sometime the traveling seismic response of the arch bridge even could be much larger than its response under the simple support excitation. Therefore it is extremely essential for the long-span structure to be considered the influence of multiple-support excitation. The Sutong bedrock wave is taken as the seismic excitation for comparing differences of seismic response of the bridge under the horizontal direction simple support excitation and traveling wave excitation.(3) According to the symmetrical structure, a simplification computational...