敏感环境下大型基坑变形控制及分析

Deformation Control and Analysis of Large-scale Foundation Excavation Under Sensitive Environment

上海某大型基坑紧邻运营的地铁线路和大型厂房,为有效减小基坑开挖对邻近建(构)筑物的影响,现场除采取常规的地基加固变形控制措施外,还采用分区开挖法,即利用多幅中隔墙将大型基坑分隔为若干小面积基坑的方法。现场监测数据表明,地下连续墙水平位移、地表沉降、邻近地铁和建筑物的变形均远小于对应的变形控制指标,这说明在敏感环境下大型基坑开挖过程中,分区开挖与地基加固相结合的方法为有效的变形控制方法。

A large-scale excavation in Shanghai soft clays was constructed nearby an operating subway station and a large factory. In order to reduce the influence on adjacent building,apart from employing the regular deformation control method such as foundation reinforcement,zoned excavation which divides large-scale excavation into several small area excavations by partition walls was also used. The field observed date shows that the horizontal displacements of diaphragm walls, subsurface settlements,deformations of nearby subway station and building are much smaller than the corresponding deformation control standards. It indicates that when large-scale excavation construct under sensitive environment,zoned excavation combined with foundation reinforcement is an effective deformation control method.