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

采用二维模型试验和弹塑性有限元分析方法，研究了施工历史、墙体摩擦力、墙体刚度和支板对地面运动和墙体土压力的影响。试验结果表明，在墙体最终挠度相同的情况下，回填体的地表沉降量和墙体上的土压力取决于墙体挠度的变化过程。墙体摩擦力、墙体刚度、支杆位置和刚度对墙体土压力和地面运动（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，计算结果充分考虑了土与结构的力学特性、土与墙界面的力学特性以及开挖过程。这种对墙的挠度、墙的土压力和包括开挖下地表沉降在内的地面移动的影响在目前的设计实践中尚未得到评估。

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.