软土地区基坑围护结构抗震性能数值模拟研究

Numerical Simulation Study on Aseismatic Behaviour of Retaining Structure for Foundation Pit in Soft Soil Area

为研究软土地区常用基坑支护结构形式的抗震性能,分别建立了基坑的重力式、悬臂式、内支撑式以及锚拉式围护结构的有限元模型,分析了水平地震作用下不同支护结构与土体的动力响应规律,以及基坑的整体稳定性特征。研究发现,地震荷载作用下,基坑支护结构及场地土体的力学状态均发生一定程度的劣化,其中内支撑和锚拉式围护结构的塑性区和结构内力的变化幅度显著低于重力式和悬臂式围护结构,因此其抗震效果优于后两者。

In order to study the seismic safety of difference retaining structures for foundation pit in soft soil area,some finite elements models are made to simulate the gravity type,cantilever type,interior retaining type and sheet-pile type retaining structure of foundation pit.The dynamic response performance and the whole safety of retaining structure are analyzed.The simulation results show that the mechanic status of retaining structure and soil became worse under the seismic load.The results of plastic zone and the internal force show that the interior type and sheet-pile type retaining structure are much safer than other retaining structure patterns.