刘家峡大桥非一致激励地震反应分析

Analysis on Seismic Response of Liujia Gorge Bridge under Non-uniform Excitation

摘要:

地震波在向四周传播的过程中，不仅有时间上的变化特性，而且在空间上也存在着明显的变化特性。针对刘家峡大桥两桥塔场地地震动时程相差较大且跨径较大的情况，为研究其在地震波有限性的传播速度、波相干性以及不同的局部场地地质等条件下对各支承点的地震激励，利用非一致激励地震反应分析理论，对刘家峡大桥进行了多点激励地震反应分析和地震行波效应研究。结果表明：非一致激励分析理论结果较一致激励分析理论结果更为准确，则非一致激励分析理论是对悬索桥等索吊特殊桥梁结构进行分析的更为符合实际的地震动作用效应输入模式。

Abstract:

In the process of the seismic wave propagating around, there are not only changes in time, but also obvious changes in space. Aiming at the situation of the greater difference of seismic motion time course and the longer space between two bridge pylon sites of Liujia Gorge Bridge, in order to explore its seismic excitation under the conditions of finite seismic wave propagation speed, wave coherence and different local site geologies, the seismic response analysis theory of non-uniform excitation is used to study the multi-point excitation seismic response and seismic traveling wave effect of Liujia Gorge Bridge. The result shows that the theoretical result of non-uniform excitation analysis is more accurate than the theoretical result of constant excitation analysis. Therefore, the theory of non-uniform excitation analysis is a more practical input mode of ground motion effect for special bridge structures such as suspension bridges.