基于概率密度演化的渡槽结构抗震分析

Seismic Analysis of Large scale Aqueduct Structures Based onthe Probability Density Evolution Method

摘要:

应用随机过程的正交展开方法，将地震动加速度过程展开为标准正交基函数与标准正交随机变量的线性组合形式。在此基础上采用随机函数的思想，将正交展开式中的标准正交随机变量表达为基本随机变量的函数形式，从而实现用一个基本随机变量来表达原地震动过程的目的。结合地震动过程的正交展开 随机函数模型与概率密度演化方法，对某大型渡槽结构进行随机地震反应分析与抗震可靠度计算；重点研究空槽和三槽有水等四种工况下渡槽结构控制点位移以及控制截面内力的随机地震反应与可靠度，进而获得渡槽结构控制点和控制截面的地震反应概率信息。

Abstract:

Using the orthogonal expansion method of random processes，the non-stationary seismic acceleration process is represented as a linear combination of the standard orthogonal basis functions and the standard orthogonal random variables.Then，using the random function，these standard orthogonal random variables in the orthogonal expansion are expressed as an orthogonal function form of the basic random variable.Therefore，this method can use a basic random variable to express the original earthquake ground processes.The orthogonal expansion-random function approach was used to generate 126 representative earthquake samples，and each representative sample was assigned a given probability.The 126 representative earthquake samples were combined with the probability density evolution method of stochastic dynamical systems and random seismic responses of large-scale aqueduct structures was investigated. In this study，four cases were considered；aqueduct without water，aqueduct with water in the central trough， aqueduct with water in a two-side trough，and aqueduct with water in three troughs，and probability information of seismic responses for these cases were obtained. Moreover，using the proposed method，the seismic reliability of the aqueduct structures was efficiently calculated.This method provides a new and effective means for precise seismic analysis of large-scale aqueduct structures.