渗流作用下的基坑变形分析

Deformation analysis on foundation pit excavation based on seepage effect

以深厚饱和软土地区的南京某基坑工程为例,基于地下水渗流因素对基坑变形数据系统分析,总结其在渗流作用下的变形规律。进一步借助有限元软件Midas/GTS的渗流模块,开展考虑渗流前后的基坑变形模拟分析。研究表明:考虑渗流作用下的地表沉降量较之前增加约22.9%,经分析,该部分除固结沉降外多由渗流诱使地连墙位移所致;另外,渗流力对地连墙底部作用尤为明显,其位移量较未考虑渗流增大2.9mm,故渗流作用下地连墙底部加固问题应在基坑施工时给予足够的重视。

Take a project located at the deep saturated soft soil area in Nanjing as an example, the pit deformation data were analyzed based on seepage effect and its deformation law was summarized.Then the seepage module of finite software Midas/GTS was used to carry out pit deformation simulation analysis before and after seepage. Study shows that the surface subsidence with seepage considered increases approximately 22.9% compared with that without seepage, which causes mainly by the displacement of seepage wall in addition to the consolidation settlement. ;furthermore, seepage force affects obviously on the bottom of ground wall ,which causes 2.9 mm more displacement.Therefore, enough importance should be paid to the reinforcement of ground wall bottom with seepage effect in foundation pit construction.