考虑土体空间变异性的液化区埋地管道上浮反应与易损性分析  

SEISMIC UPLIFT RESPONSE AND FRAGILITY ANALYSES OF BURIED PIPES IN LIQUEFIABLE SITES UNDER EARTHQUAKES CONSIDERING SOIL SPATIAL VARIABILITY

作　　者：李典庆[1,2] 单晟治 王顺 杜文琪 LI Dian-qing;SHAN Sheng-zhi;WANG Shun;DU Wen-qi(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan,Hubei 430072,China;Institute of Engineering Risk and Disaster Prevention,Wuhan University,Wuhan,Hubei 430072,China)

机构地区：[1]水资源工程与调度全国重点实验室(武汉大学),湖北武汉430072 [2]武汉大学工程风险与防灾研究所,湖北武汉430072

出　　处：《工程力学》2024年第9期31-41,共11页Engineering Mechanics

基　　金：国家自然科学基金项目(U2240211,52078393)。

摘　　要：为分析可液化场地土体空间变异性对管道上浮反应的影响,以土体相对密度Dr为随机场变量,采用基于乔列斯基分解的中点法生成随机场,基于OpenSees软件进行埋地管道二维随机有限元计算,分析了土体空间变异性对管道上浮位移的随机统计特征以及管道上浮易损性的影响。结果表明:当管道上浮位移较大时,土体空间变异性条件下管道上浮位移均值小于确定性分析结果,且差距随空间变异性增强而更为显著;局部致密区间的存在一定程度上限制了管道上浮行为的发展;累积绝对速度CAV可较好表征地震动强度对管道上浮位移的影响;易损性函数的离差随土体空间变异性增强而不断增加,且均大于所对应的确定性离差,导致易损性曲线更为平缓;随机变量模型不能合理表征空间变异性对管道上浮反应的影响。To analyze the influence of soil spatial variability in the liquefiable site on the uplift response of the pipe,upon the Cholesky decomposition technique with midpoint discretization,the density ratio of soil is regarded as a random field variable,and the two-dimensional random finite element computation is carried out based on OpenSees.The influence of soil spatial variability is analyzed on the random statistical characteristics of pipe uplift displacement and pipe uplift fragility.The results show that:when the pipe uplift displacement is large,the mean value of the pipe uplift displacement is smaller than the deterministic analysis result considering soil spatial variability,and the difference becomes more significant with the increase of spatial variability;the existence of local denser zones restrains the development of the severe uplift behavior of the pipe to a certain extent;the cumulative absolute velocity CAV can better characterize the effect of ground motion intensity on the pipe uplift displacement;the dispersion of the fragility function increases with the increase of soil spatial variability and is greater than the corresponding deterministic deviation,resulting in a flatter fragility curve;and the random variable model can not reasonably characterize the effect of spatial variability on the pipe uplift response.

关 键 词：液化场地 土体空间变异性 随机场 管道上浮 地震易损性 

分 类 号：TU435[建筑科学—岩土工程]