参数空间变异性下坝基防渗墙地震反应  

Seismic Response Analysis of Cut-Off Wall of Dam Foundation Under Spatial Variability of Parameters

作　　者：张富有[1] 周强强 杜鹏程 ZHANG Fuyou;ZHOU Qiangqiang;DU Pengcheng(College of Civil Engineering and Transportation,Hohai University,Nanjing 210024,China)

机构地区：[1]河海大学土木与交通学院,南京210024

出　　处：《上海交通大学学报》2022年第5期684-692,共9页Journal of Shanghai Jiaotong University

基　　金：长江水科学研究联合基金重点支持项目(U2040221)。

摘　　要：堆石坝覆盖层土体类型复杂,结构松散且有时存在透镜体,使得覆盖层材料参数存在空间变异性,地震作用下对坝基防渗墙应力变形存在不可忽视的影响.在蒙特卡罗框架下,采用Cholesky分解的高斯空间随机场离散方法,利用Python对Abaqus进行二次开发,实现了覆盖层材料空间变异性的“非侵入式”随机有限元分析.研究结果表明:考虑覆盖层材料空间变异性的情况下防渗墙不同部位的应力变形均有不同程度的超标,且动应力的变异系数大于动位移的变异系数,显示覆盖层材料参数的变异性对防渗墙在地震作用下的应力变化更敏感.因此在设计阶段应考虑这种不确定性,以确保坝基防渗墙的安全运行.The overburden of rockfill dams has complex soil types, loose structures, and sometimes lenses, which make the material parameters of the overburden have spatial variability, and the impact of earthquakes on the stress and deformation of the dam foundation cut-off wall cannot be ignored. Under the framework of Monte Carlo, by using the Gaussian spatial random field discrete method of Cholesky decomposition, the secondary development of Abaqus with Python is used to realize the “non-invasive” stochastic finite element analysis of the spatial variability of the overburden material. The research results show that considering the spatial variability of the cover material, the stress and deformation of the different parts of the cut-off wall have different degrees of excess, and the coefficient of variation of dynamic stress is greater than that of the dynamic displacement, indicating the variability of the material parameters of the cover is more sensitive to the stress changes of the impervious wall under the action of earthquake. Therefore, this uncertainty should be considered in the design stage to ensure the safe operation of the dam foundation impervious wall.

关 键 词：覆盖层 防渗墙 空间变异性 随机有限元 地震反应 

分 类 号：TV641[水利工程—水利水电工程]