土石坝地震永久变形的危险性分析

本文将地震地面运动模拟为零均值平稳高斯随机过程,以Newmark滑块模型为基础,建立了土石坝地震永久变形的概率分析模型,利用Monte-Carlo数值模拟检验,证明了在随机地震作用下土石坝永久位移服从正态或对数正态分布,通过大量综合计算,给出了永久位移概率分布参数与可能滑动体平均地震加速度功率谱参数之间的经验关系,针对一个算例,对土石坝地震永久位移进行了危险性分析。

Risk Analysis of Earthquake-Induced Permanent Deformations Occured in Earth and Rockfill Dams

In this paper, the earthquake ground motion is simulated as a zero-mean Gaussian stationary process. On the basis of Newmark’s sliding block idea, a probability analysis model is developed for evaluating the earthquake-induced permanent deformations occured in earth and rockfill dams. The numerical results obtained by Monte-Carlo approach show that the probability distribution of the permanent deformation follows the normal or lognormal distribution. A large amount of calculated data are analyzed and synthesized, the emperical formulae are presented to predict the parameters of the probability distribution and of the average acceleration power spectra of the sliding block. An example of the risk analysis of permanent deformation is given.