非一致激励下李渡长江大桥的地震响应分析

在已有地震危险性评价成果的基础上,基于随机过程理论关于幅值、相位与功率谱的关系式,采用二维相干非一致激励功率谱模型,根据场地地震动参数合成人工地震波,考虑地震波的传播效应和多点激励效应,分析了李渡长江大桥（斜拉桥）在地震激励下的空间几何非线性响应特性,计算了桥梁结构关键部位在地震力作用下的响应特性,并与一致激励下对应响应量进行比较,认为非一致激励下大跨斜拉桥关键部位的某些响应量大幅度增加,说明了进行非一致响应分析的必要性。

Analysis on seismic response of the great Lidu Changjiang bridge subjected to asynchronous excitation

The artificial seismic waves were simulated according to the earthquake parameters of the site,with the relationship between amplitude,phase angels and power spectra in stochastic process being used and a two-dimensional coherency function-an asynchronous excitation power spectral density(PSD) model being employed as well,which were based on the results of seismic risk assessment.The great Lidu Changjiang bridge(cable stayed bridge) subjected to the asynchronous seismic excitations was analyzed,during which course the effects of geometric nonlinear was considered.Several results of concerned sections under asynchronous excitation and synchronous excitation were supplied,between which comparison showed the some responses amplifying with asynchronous condition.Conclusions supported the necessity of asynchronous responses analysis.