超大型深基坑工程部分逆作法施工过程三维有限元模拟

3D FEM simulation of excavation construction process of oversized deep foundation pits by use of top-down construction method

对于超大型深基坑开挖和地下结构施工,采用部分逆作法施工是比较经济而有效的。但部分逆作法基坑开挖施工是一个复杂的系统问题,为了检验设计计算的可行性和掌握支护结构力学响应的发展特点,有必要对基坑开挖进行数值模拟预测。结合上海仲盛商业中心大型深基坑工程,根据基坑开挖施工的特点,建立了三维数值计算模型,对基坑开挖施工过程进行动态数值模拟预测。通过对模拟结果与实测数据的分析比较,结果表明:三维有限元分析能较好地模拟基坑开挖引起支护结构的变形与应力和周围土体的变形。

In the design and construction of oversized foundation pits,the partly top-down construction method is economical and effective.But the excavation process by use of the partly top-down construction method is a complex systematic project.In order to check the design and to find out the development property of the mechanical response of the supporting structure,the numerical simulation is necessary.Combined with the large deep pit engineering of Shanghai Zhongsheng Commercial Center, a 3D FEM analysis model was established to simulate the process of excavation work.The calculated results were compared with the monitored data.It shows that the 3D FEM analysis of the excavation can reveal the deformation of the diaphragm walls and the surrounding solid quite well.