基于ANSYS的三维自由场地震动反应分析

Seismic response analysis of three-dimensional free field based on ANSYS

为探究自由场地震反应的基本规律和考虑土-结构相互作用(SSI)时的整体结构地震反应分析提供参考,采用ANSYS建立了三维自由场有限元模型,分别考虑了同一场地在三种不同水平两向基岩输入地震动以及三种不同类型场地在同一水平两向基岩输入地震动下的两种情况,对其进行了地震反应分析。通过对比和分析得到的各类场地地表中心点的绝对加速度、相对位移、各层土体的层间位移峰值以及绝对加速度峰值等指标,得出一些关于此类问题的有用结论,供工程设计及后续研究时参考。

To investigate the basic rule of free field seismic response and provide reference for the whole structural seismic response analysis considering soil-structure interaction（SSI） ,a 3D free field finite element model was established using the finite element code ANSYS,the reasonable field free boundary width was confirmed by an example. The seismic response analysis was carried out considering two circumstances respectively, same field under three different two-horizontal bedrock ground motion inputs and three different fields under same two-horizontal bedrock ground motion input. Some useful conclusions are obtained by comparing and analyzing absolute acceleration time history, relative displacement time history of each field surface central point, story drift peak value, absolute acceleration peak value of each soil layer. These results provide reference for engineering design and further research.