考虑空间效应的多支撑管线随机地震响应分析

Random Seismic Analysis of Multi-Supported Pipelines Subjected to Spatially Varying Ground Motions

提出了一种能考虑地震动空间变化效应的多支撑管线随机地震响应分析的解析方法.证明了多点地震作用下结构的平稳随机响应分析可转化为求解支座简谐运动时的确定性响应,直接给出了含有待定系数的简谐响应的形式,并通过边界条件和连续性条件建立待定系数的求解方程.与拟静位移分解法相比,该方法不用计算结构的振型以及拟静位移分量,完全是基于解析推导,因此在计算效率方面优势明显.数值算例中,采用该方法和拟静位移分解法计算了一个6跨管线在空间多点地震作用下的随机响应,对比验证了方法的正确性和高效性.

An analytical method was formulated for the random seismic analysis of multi-supported pipelines subjected to spatially varying ground motions. With the pseudo-excitation method, the stationary random seismic responses were proven to be represented in terms of deterministic responses of pipelines under multi-support harmonic excitations. The harmonic responses were expressed as a series of harmonic functions with undetermined coefficients, which could be solved with the appropriate boundary and compatibility conditions. In compari- son with the quasi-static decomposition method, the present method is derived analytically without computation of the structural normal modes and quasi-static components. The high accuracy and efficiency of the present method is verified through its application to an exemplary 6-span pipeline and the comparison of results made with those from the quasi-static decomposition method.