地铁车站-隧道连接段结构地震响应分析

为了研究地铁车站-隧道连接段结构的地震响应规律,为其抗震设计提供依据,根据天津地铁一号线的实际工程背景,对地铁车站-隧道连接段结构建立有限元模型,并进行弹塑性动力时程分析.着重从地下结构柱和侧墙的内力响应、位移响应,结构整体变形以及车站与隧道连接墙应力响应等方面考察地铁结构在多遇、偶遇和罕遇地震激励下的抗震性能.结果表明:在地震作用下,地铁车站的中柱顶、底端出现动拉压应力,侧墙与各层楼板连接处应力较为集中;车站-隧道连接墙体上的隧洞口周围出现很明显的应力集中现象;车站侧墙变形从底板沿高度增加,中柱由于受力复杂呈现"S"型破坏模式.在实际工程中应针对这些薄弱环节采取相应的加固措施,研究成果可为地下工程的抗震设计提供理论依据与参考.

Seismic Response Analysis of Station-Tunnel Transition Section Structure

To study the seismic response of station-tunnel transition section structure and provide reference for its seismic design,according to the practical engineering background of Tianjin metro line1,the finite element model of station-tunnel transition section structure and its dynamic analysis are established. Seismic performance of the structure under three different levels of earthquake is investigated mainly based on internal forces and displacement response of pillars and sidewalls,stress response of station-tunnel transition wall and integral deformation. Results show that dynamic tensile and compressive stresses occur at both the top and bottom of center pillars. Stress concentration appears at the junction of sidewalls and floors, as well as around the tunnel portals on the station-tunnel transition wall.Deformation of sidewalls vertically increases from the bottom up. Due to the complicated forces,center pillars show "S"type failure mode. As a result,appropriate reinforcement measures should be taken against these weaknesses in actual project. The related conclusions can provide theoretical basis and reference for seismic design of underground engineering research.