基于波场分离的不规则地形下地震波输入方法  

INPUT METHOD OF SEISMIC WAVE IN IRREGULAR TERRAIN BASED ON WAVE FIELD SEPARATION

作　　者：张佳文 李明超[1] 韩帅 闫文钰 ZHANG Jia-wen;LI Ming-chao;HAN Shuai;YAN Wen-yu(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300350,China;Smart Construction Laboratory,Department of Architecture and Real Estate,The Hong Kong Polytechnic University,Hong Kong 999077,China)

机构地区：[1]水利工程仿真与安全国家重点实验室,天津大学,天津300350 [2]香港理工大学建筑与房地产学系智能建造实验室,中国香港999077

出　　处：《工程力学》2023年第11期69-80,109,共13页Engineering Mechanics

基　　金：国家自然科学面上基金项目(51879185);天津市研究生科研创新项目(2021YJSB138)。

摘　　要：不规则地形条件下斜入射地震波场求解难度较大,以往的方法在计算精度和适用范围方面仍有不足。该文结合解析推导和有限元模拟,提出了一种基于波场分离技术的不规则地形条件下地震波输入方法,将地震P波和SV波在不同边界下进行波场分离:垂直入射时在侧面边界上分离为自由波场和散射波场,底部边界上分离为入射波场和边界外行场;斜入射时将输入侧对面的边界改为分离成入射波场和边界外行场;并充分考虑局部地形条件的影响,还基于改进的波动方法以便捷地输入节点力。同时对比了多组不同地震入射角度下规则场地和不规则场地的振动反应。结果表明:该方法在多类地形条件下计算精度与效率均较高,适用范围广且易于推广至复杂场地条件,并发现地震波入射角度和局部场地条件对地表位移响应影响较大。该研究可为不规则地形条件下的振动响应分析提供有效的手段。Solving the oblique incident seismic wave field under irregular terrain conditions is challenging,and previous methods are limited in calculation accuracy and application range.A ground motion input method was proposed for irregular terrains based on wave field separation by combining analytical derivation and finite element simulation.Seismic P waves and SV waves are separated under different boundary conditions.When incident vertically,they are decomposed into free wave field and scattered wave field at the side boundary,and incident wave field and boundary outer field at the bottom boundary.For oblique incidence,the seismic wave at the opposite boundary of the input side is separated into incident wave field and outer boundary field.In this paper,the influence of local topographic conditions was fully considered,and the improved wave method was used to input nodal force conveniently.Besides,the vibration responses of regular and irregular terrains under different incidence angles were analyzed.The results show that the method has high computational accuracy and efficiency under multiple topographic conditions and can be applied to complex site conditions.Moreover,the incident angle and local site conditions are found to have significant effects on surface displacement response.The study can provide an effective way for response analysis under irregular terrain conditions.

关 键 词：场地反应 不规则地形 地震波输入 地震波场分离 入射角度 

分 类 号：P315.9[天文地球—地震学] TV312[天文地球—固体地球物理学]