南京德基广场二期基坑支护设计

南京德基广场二期工程位于南京市中心区域,主楼区普遍开挖深度21.50m,附楼区普遍开挖深度19.70m,基坑开挖深度较深,基坑面积巨大.本文通过分析该工程的建筑结构方案、场地的工程地质条件和水文地质条件、周边环境等因素,提出了基坑周边全部采用两墙合一的地下连续墙作为基坑围护结构,并且附楼逆作法施工,结合主楼顺作法施工的设计方案.在此基础上,本文提出了相应的地铁隧道保护措施.另外本文采用通用有限元分析软件,取邻近地铁侧的典型剖面计算基坑开挖对地铁隧道的影响,计算结果显示该工程采用逆作法施工对周围环境影响较小,能满足地铁运营对隧道变形提出的要求.本文对采用逆作法施工的工程具有一定的指导意义.

FOUNDATION PIT SUPPORT DESIGN OF NANJING DEJI PLAZA(PHASE 2) IN DENSE URBAN AND ADJACENT TO SUBWAY TUNNEL

The Nanjing Deji Plaza(Phase 2)project is located at the center of Nanjing. Excavation depths of main building and attached building are 21.50m and 19.70m respectively. The excavation depth of the foundation pit is deep. The pit area is huge. This paper analyzes the project structure, engineering geological conditions, hydrogeology conditions, surrounding environment and especially protection of subway tunnel. Pit support structure adopts underground diaphragm wall with two walls joining together. The attached building is constructed with top-down method. The main building is constructed with down-top method. This paper has put forward the protection measures to subway tunnel. In addition, this paper uses the general finite element analysis software to calculate the influence to subway tunnel by foundation pit excavation. The results show that this project has little impact on surrounding environment using top-down method, and meets the requirement of tunnel deformation with metro operation. This paper has a certain guiding significance for the projects with top-down method.