三维层状地基空沟主动隔振分析

3-D Analysis of Active Vibration Isolation by Open Trench in Layered Ground

基于薄层法在研究层状介质中波的传播问题的高效性、边界单元法处理无限域问题的精确性,结合二者的优点提出三维层状地基薄层法基本解答,建立了基于三维层状半空间薄层法位移基本解答的半解析动力边界元法。该方法可有效的分析多层场地的动力问题,解决土-结构动力相互作用问题。同时分别对粘弹性上软下硬地基及上硬下软地基的三维空沟主动隔振进行了详细的分析。结果表明,两种情况下采用空沟屏障隔振均可以取得一定的隔振效果;同时,地基分层参数对空沟隔振体系的隔振效果影响显著。

Thin-layered method （TLM} is very efficient to study the wave propagation in layered media, and boundary element method （BEM） is very precise to solve infinite domain problems. Combining the advantages of two methods, the BEM, in which Green function is as fundamental solution of stratified half-space obtained by TLM, is used in this paper for analyzing the dynamic problems in stratified foundation. It is an efficient tool for dynamic soil-structure interaction problems. The effects of active vibration isolation by 3D open trench in rigid upper layer and soft lower layer or soft upper layer and rigid lower layer visco-elastic foundations are analyzed in detail. The results show that vibration isolation effect can be relatively good in both cases. The vibration isolation effect is greatly affected by the parameters of layered foundation.