基于优化选点的土层剪切波速随机性对地铁车站结构抗震性能的影响研究  

Influence of soil random shear wave velocity on seismic performance of subway station structure based on optimal point selection strategy

作　　者：樊一凡 陈之毅[1] Fan Yifan;Chen Zhiyi(Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学,上海200092

出　　处：《土木工程学报》2023年第8期174-183,共10页China Civil Engineering Journal

基　　金：国家重点研发计划(2022YFE0104400)。

摘　　要：地铁车站结构是城市生命线工程的重要节点。地下结构的地震响应主要受土体变形控制,自然土层分布具有很强的不确定性,分析土层参数随机性对地铁车站结构抗震性能的影响是非常有必要的研究。然而,应用传统蒙特卡罗模拟方法解决非线性土-地铁车站结构系统的随机动力学问题会耗费大量的计算成本。为此,文章首先建立土-结构相互作用有限元模型,构建随机地震动变量和随机土层剪切波速变量,采用一种优化选点策略用于降低非线性动力时程分析的计算成本,讨论了土层剪切波速随机性对地铁车站结构抗震性能的影响。分析结果表明:相比于传统抽样方法,Sobol序列抽样方法在保证计算精度的前提下有效降低了非线性动力时程分析的计算成本;不考虑土层剪切波速随机性时,层间位移角响应分布范围小而集中,潜在震害风险会被忽视,地铁车站结构的抗震可靠度也会被高估,在今后的抗震分析与设计中有必要将土层剪切波速随机性纳入考虑。Subway station structure is the important node of urban lifeline engineering.The seismic response of underground structure is mainly controlled by the soil deformation,while the distribution of natural soil layer has strong uncertainty.It is very necessary to analyze the influence of the randomness of soil layer parameters on the seismic performance of subway station structure.However,using the traditional Monte Carlo simulation method to solve the stochastic dynamics problem of nonlinear soil subway station structural system will cause much computational cost.Therefore,this paper establishes the finite element model to simulate the soil-structure interaction,and constructs the random ground motion variables and random soil shear wave velocity variables.An optimal point selection strategy is adopted to decrease thecomputational cost of nonlinear dynamic time history analysis,and the influence of the randomness of soil shear wave velocity on the seismic performance of subway station structure is discussed.The analysis results show that compared with the traditional sampling method,Sobol sequence sampling method effectively can reduce the calculation cost of nonlinear dynamic time history analysis with enough calculation accuracy.When the randomness of soil shear wave velocity is not considered,the distribution range of inter-storey drift ratio response is small and concentrated.The potential seismic damage risk will be ignored,while the seismic reliability of subway station structure will be overestimated.In the future seismic analysis and design of subeway station stuucture,it is necessary to take the randomness of soil shear wave velocity into account.

关 键 词：地铁车站结构 剪切波速 随机变量 选点策略 抗震性能 

分 类 号：TU352.1[建筑科学—结构工程] TU93