软土深基坑支护内力和变形的三维有限元分析

针对天津经济技术开发区某软土深基坑工程，采用大型有限元分析软件ABAQUS对基坑支护体系的内力、变形进行了全三维非线性有限元分析：应用单元生死功能精确地模拟实际开挖过程；为减小不同类型单元自由度耦合引起的计算误差，对土体及支护体系均采用实体单元模拟；通过数值分析结果与实际测量数据的比较，验证了分析方法的精度，计算方 法及结论有益于今后对类似基坑工程进行更可靠的分析设计。

Internal force and deformation by 3D finite element analysis of support system of a typical deep excavation on soft ground

The three-dimensional finite element analysis (3D FEA) of support system is carried out with the help of ABAQUS. It is about the internal force and deformation of a typical deep foundation pit during the foundational construction at Tianjin Economical Development Area (TEDA), which is famous for its soft ground. The method of active and inactive element can simulate the excavation progress better; and also solid elements for soil and support system are employed in order to reduce the error produced by degree-of-freedom coupling of different kinds of elements. By comparing the internal force and deformation of the support system of theoretical analysis with the results of field monitoring, it shows that the accuracy of 3D FEA is sufficient for theoretical analysis. The method and conclusions are useful for other similar projects of design and construction of deep foundation pit on soft ground.