The Study Of Pounding Analysis Of Seismic Response For Long-span Cable-stayed Bridge

Cable-stayed bridge has became the most prevalent bridge style because of its advantages of long span, light weight, and less restricted by clearance under the bridge and deck elevation, etc. The pounding damage at expansion joints of cable-stayed bridge during earthquakes would increase the risk of cable-stayed bridge. As a result, the studies on the pounding damage at expansion joints of long span cable-stayed bridge and its approach bridges during earthquakes are of great significance rational value.The research was focused on a cable-stayed bridge with two approach bridges of 4×40m bilateral symmetrical continuous beam. Midas civil was adopted to establish structural dynamic calculation model. Combining with dynamic time history analysis method, the pounding effects of adjacent girders at expansion joints on seismic responses of main bridge and approach bridges are studied.The main contents of the study are as follows:(1)Bridge structure pounding analysis theories were introduced, especially Pounding vibration theory model and pounding process of a cable-stayed bridge with a approach bridge.(2)Spatial finite element analysis model was established to analyze the whole structure eigenvalue.(3)E1 response spectrum method and E2 time history method are adopted to obtain the seismic response of structure. According to contrastive analysis, the influences of pile-soil interaction patterns and pier height on structure seismic response are determined.(4)During the respective effect of ChiChi seismic wave, WenChuan seismic wave and Ya’an seismic wave, the nonlinear time-history analysis is adopted to contrastive analyze the difference factors’ influence on seismic response of bridges with two sided or one sided pounding, mainly including pounding force and times, the girder displacement of main bridge and approach bridge, the internal force of pier and tower bottom, the displacement of tower top.(5)The pounding effect of main factors was discussed to explicit the influence of the structure of pounding, especially the input direction of seismic wave, the initial gap of pounding element, the stiffness of contact element. Some useful conclusions for seismic design of long-span cable-stayed bridges are drawn at last.The research can take significance theory reference for seismic design of long-span cable-stayed Bridges and its approach bridges.