Stress-deformation behavior of ground under excavation and development of new design methods

通过二维模型试验和弹塑性有限元分析，研究了施工历史、墙体摩擦力、墙体刚度和支撑等因素对基坑开挖过程中地表移动和墙体土压力的影响。试验结果表明，即使墙身最终挠度相同，回填土表面沉降和墙身土压力也取决于墙身的挠度过程。墙体摩擦力、墙体刚度、支撑的位置和刚度对墙体上的土压力和地表移动包括地表沉降有显著影响。计算结果较好地反映了模型试验的结果，较好地考虑了土与结构的力学特性、土与墙的接触面特性以及开挖过程。在目前的设计实践中，这种影响对墙的挠度，墙上的土压力和地面移动，包括开挖下的地表沉降尚未评估属性。

Two-dimensional model tests and elastoplastic finite element analysis for excavation problems with braced wall are performed to investigate the influence of construction history , the wall friction, the wall stiffness and the struts on the ground movements and the earth pressure on the wall. Test results show that the surface settlements of the backfill and earth pressure on the wall depend on the deflection process of the wall, even if the final wall deflection are the same. The wall friction, the wall stiffness and the position and stiffness of strut affect significantly the earth pressure on the wall and the ground movement including the surface settlements. The computed results, in which mechanical behavior of soil and structure, behavior of interface between soil and wall and the process of excavation were property taken into consideration, describe well the results obtained in the model tests. Such influence on the deflection of the wall, the earth pressure on the wall and the ground movements including surface settlements under excavation has not been evaluated property in the present design practice.