软土地区深大基坑分区开挖力学效应数值模拟

以上海世博地下变电深大基坑工程为背景，基于ＡＢＡＱＵＳ软件，通过二维弹塑性有限元数值模 拟的方法，分析深大基坑的分区开挖力学效应，监测分析围护体测斜、水平位移、垂直位移、支撑内力、分 层沉降、孔隙水压力分布等随时间变化规律。研究结果表明:深大基坑开挖施工会对周边环境产生影 响，至支撑拆除期间，变化量在一个可控的范围内变动而且地表位置差异沉降较小，其余各监测项目沉 降数据都比较稳定未发生较大的突变，周边环境以及基坑结构自身变形均处于受控状态。研究成果可 为今后类似工程提供理论指导。

Numerical Simulation of Mechanical Effect for Deep and Large Foundation Pit Excavation in Soft Soil Region

Based on the deep foundation pit project of Shanghai Expo underground substation ,the two-dimensional elas-tic-plastic finite element numerical simulation method is adopted to analyze the mechanical effect of excavation in deep and large foundation pit based on ABAQUS .Monitoring and analysis of retaining inclinometer and horizontal displace-ment ,vertical displacement and internal force of supporting structure ,layered settlement and pore water pressure distri-bution with time variation .The results show that the construction will have an impact on the surrounding environment of excavation of deep foundation pit ,to support the demolition period ,the variation of changes in a controllable range of po -sition and surface differential settlement is small ,the rest of the monitoring project settlement data are more stable and not the larger mutation ,the surrounding environment and the structure of its foundation pit deformation are in a controlled state .The research results can provide theoretical guidance for similar projects in the future .