基坑开挖对周边环境及地铁高架影响的数值分析

Numerical Analysis of the Influence of Foundation Pit Excavation on the Surrounding Environment and Subway Elevated

南京仙林中心区D3地块基坑工程,基坑开挖深度为11.9m,基坑侧壁土体基本为素填土和粉质粘土层。基坑整体采用钻孔灌注桩结合两道混凝土内支撑支护,并采用全止水帷幕。基坑南侧距地铁二号线高架桥立柱的距离为23.7m^28.6m,为了分析基坑开挖对周边环境及地铁高架的影响,通过数值模拟方法分8个分析步模拟整个开挖过程。数值计算结果表明了采用该支护方案后基坑土方开挖对周边环境的影响范围较小,对地铁高架几乎没影响,保证了地铁高架的安全。

Nanjing Xianlin center zone D3 block foundation pit excavation depth of 11.9m, foundation pit wall soil basic for grain filling soil and silty clay layer. The whole excavation of the bored pile with two concrete supporting, and the waterproof curtain. On the south side of foundation pit from the subway No.2 line viaduct column distance for 23.7m ~28.6m, in order to analysis of foundation pit excavation on the influence of the surrounding environment and the subway elevated. By numerical simulation method eight analyses step to simulate the whole process of excavation. The results of numerical calculation show that the influence of the excavation on the surrounding environment of the foundation pit is small, which is almost no influence to the subway overhead, which ensures the safety of the subway elevated.