Traveling Wave Effect Theory And Seismic Vulnerability Analysis Of The Long-span Rigid Frame-continuous Composite Girder Bridge

As bridge as a engineering structure is relatively important in traffic, its security, applicability and durability for people is getting more and more attention. In recent decades, the continuous development of bridge construction in our country, with the development of traffic demands, long-span continuous girder bridge in the bridge project has been more widely used, and the economy and safety of large bridges for countries and people have a more significant impact.In this paper, the long-span rigid frame-the travelling wave effect of continuous composite girder bridge is studied, the assumption that pier foundation in seismic amplitude and frequency spectrum characteristics unchanged under the premise of the bridge dynamic analysis model is established. Ele vated were studied using the dynamic time history analysis method to the traveling wave effect of the bridge pier base bending moment and displacement of the seismic response of the change. Results show that:(1) under the action of travelling wave effect, the seismic response of the bearing displacement amplification effect compared with the same input, engineering should be fully considered in the construction of the negative influence of traveling wave effect, the further away from the pier beam consolidation in support, the amplification effect, the more obvious, and therefore should be considered when designing this type of bridge enough reserve of displacement; (2) under the action of travelling wave effect, the bottom of the bridge pier bending moment exists amplification effect, position of different piers, bending moment increase effect is different, and the traveling wave effect of the pier base bending moment has obvious directivity, along the direction of seismic wave propagation, the pier base bending moment decreases. (3) the traveling wave effect of long-span rigid frame-the influence of the continuous composite girder bridge are mainly concentrated on the set of bearing and the corresponding support piers, and presents the seismic wave propagation velocity is smaller, the greater the influence of trend; For the double column type of pier girder consolidation the influence of rectangular solid pier is small.This article also for long-span rigid frame-the key position of continuous composite girder bridge seismic vulnerability of numerical analysis, and draw out the theory of seismic vulnerability curve. First of all, through the analysis of the existing bridge seismic damage, it is concluded that the long-span rigid frame-vulnerable regions of continuous composite girder bridge is mainly piers and bearing, and main piers of the bridge of a certain article 20 seismic wave, determines the pier vulnerability is the key position of the pier top and bottom of the pier. Comparative analysis as the ground motion intensity index, the discreteness of PGA calculation results than using the SA, so the calculation SA as a result of the ground motion intensity measures give more accurate. In this paper, using the nonlinear least squares were plotted and cross at ele vated bridge to bridge piers under the action of seismic wave and the bearing of seismic vulnerability curve, through to the end of each bridge pier top and pier vulnerability curve comparison between and comparing the different piers parts same vulnerability curve found that block bottom than the pier top easily damaged; Than ele vated bridge piers under horizontal seismic action and support to under seismic action are more easily damaged.