地震作用下土-深埋地下结构相互作用的高效时程分析方法  

Efficient Analysis for Seismic Soil-structure Interaction with Deep Burial Depth

作　　者：赵密[1] 李旭东 高志懂 杜修力[1] ZHAO Mi;LI Xudong;GAO Zhidong;DU Xiuli(Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technolo-gy,Beijing 100124,China)

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124

出　　处：《防灾减灾工程学报》2021年第1期39-45,54,共8页Journal of Disaster Prevention and Mitigation Engineering

基　　金：北京市自然科学基金杰出青年科学基金项目(JQ19029);中国教育部创新团队(No.IRT_17R03);国家973计划项目(2015CB057902);国家自然科学基金项目(51421005,51678015)资助。

摘　　要：基于黏弹性边界和将场地地震反应转化为等效荷载的有限元直接法是目前进行地震作用下土-结构相互作用分析的常用时程分析方法之一。当结构埋深较深时,整个土-结构系统的有限元模型自由度数目较多,尤其对于三维问题,计算效率低。提出一种高效分析方法,即一维场地反应分析仍然针对整个深厚土层,在后续的土-结构相互作用分析中将土-结构计算模型的自由表面向下移动、底边界面向上移动到接近结构的位置,通过缩减土-结构相互作用模型尺寸来提高计算效率。采用理论分析与数值算例,通过与采用整个深厚土层的传统土-结构相互作用分析结果对比,说明提出的高效分析方法能够满足精度要求,并且针对不同结构尺寸、结构埋深和围岩等级给出上、下人工边界位置的建议。The direct finite element method has been widely used in the soil-structure interaction(SSI) analysis.It is achieved by transforming the site response into the equivalent loading based on the viscous-spring boundary condition.When the structure is deeply buried in the soil,the whole finite element model of the SSI system contains too many degrees of freedom,especially for the three-dimensional problem,so that the computation efficiency is low.In this paper,an efficient analysis scheme is developed.In this new scheme,the one-dimensional site response analysis is still performed for the whole deep soil layer.Subsequently,the artificial bottom and top boundaries of the SSI model are moved up from the bottom of the actual soil layer(bedrock surface) and down from free surface,respectively,to the locations sufficiently near the structure.The theoretical analysis and numerical examples indicate that the proposed efficient analysis scheme satisfies the requirements of precision,even when the location of the artificial boundary is sufficiently near the structure.The boundary location is discussed based on some parametric analyses regarding the structure size,its buried depth and the surrounding rock grade.

关 键 词：土-结构相互作用 场地反应 深埋地下结构 人工边界条件 地震动输入 参数分析 

分 类 号：TU443[建筑科学—岩土工程]