内撑式倒挂壁法对兰州市深基坑支护适用性的现场试验研究

通过对现场典型地层的工程地质特征进行分析总结,探讨了采用内撑式倒挂壁的深基坑开挖支护工法对兰州市城市轨道交通工程深基坑开挖遇到地层的适用性。为了验证内撑式倒挂壁深基坑开挖支护工法的施工可行性,使用Slide滑坡计算软件对基坑边坡开挖支护前后进行了稳定性分析,并在计算结果的基础上对基坑进行试验性开挖、支护。结果表明:有内撑倒挂壁施工方法可以有效减小对工程赋存环境的不利影响,其结构体本身作为围护结构的支撑体系,刚度较高,可显著减小围护结构及周边环境的变形。内撑式倒挂壁的深基坑开挖支护工法能够保证深基坑的稳定性,可为兰州市城市轨道交通工程深基坑临时开挖作业设计提供参考。

Field experimental study on suitability of inverted retaining wall with internal bracing in deep foundation pit in Lanzhou area

By analyzing the engineering geology conditions of stratigraphic unit, the applicability the deep foundation pit supported with inverted retaining wall in Lanzhou metro engineering is discussed. In order to validate the feasibility of inverted retaining wall with internal bracing acting on deep foundation pit, the slope stability before and after supporting is analyzed with the landslide calculation software named Slide. The deep foundation pits are excavated and supported experimentally according to the calculation. The results show that inverted retaining wall with internal bracing could effectively reduce the adverse impact on surrounding environment in deep foundation pit engineering. And the inverted retaining wall as a part of supporting structure system could decrease the deformation significantly. The inverted retainingwall with internal bracing could ensure the stability of deep excavation and could be applied to the deep foundation pit of metro line in Lanzhou city.