盆地面波效应作用下地铁车站动力响应分析

Dynamic Response Analysis of Subway Stations Affected by Basin Surface Waves

为探究浅埋地下结构在盆地面波效应作用下的地震反应特性,文章以北京某两层两跨箱型框架结构地铁车站为工程背景,利用FLAC有限差分软件,针对盆地面波效应作用与单一地震波作用下地铁车站的动力响应进行了分析对比。分析结果表明,在盆地面波效应作用下地下结构的动力响应有明显的放大作用,且随着地下结构深度的增加,相应部位的放大系数有所减小;在盆地面波效应作用下没有改变原有地下结构抗震薄弱点位置;在盆地面波效应作用下,地震波的地震动特性对地下结构的影响起着非常重要的作用。

In order to explore the characteristics of the seismic response of shallow-depth underground structures affected by basin surface waves, a comparative analysis regarding the dynamic response of subway stations under the effects of a basin surface wave versus a single seismic wave was performed with FLAC finite-difference software using a double-layer two-span box framework of a subway station as an example. The results show that： the dynamic response of underground structures is amplified under the basin surface wave effect and the amplifying factors of rel- evant parts are reduced to some extent with an increased structure depth; the weak points of underground structures are not changed under the basin surface effect in light of aseismicity; and it plays a key role in the ground motion characteristics of a seismic wave on underground structures.