考虑拆撑影响软土深基坑施工过程力学特性研究

对软土深基坑开挖支护和拆撑过程进行了三维数值模拟,计算分析了基坑开挖支护与拆撑施工全过程土层、结构力学特性。结果表明:软土基坑围护结构与土层间错动较为显著,因软土层极限剪应变很小,局部出现滑移破坏;基坑拆撑过程对围护结构的受力变形产生了显著的影响,基坑设计施工应给予充分考虑;软土基坑开挖表现出了较强的时间效应,应减小软土基坑的暴露时间,及时施作垫层及底板,以有效控制位移和内力。

Three-dimensional numerical simulation for soft soil foundation during excavating and dismantling shoring was conducted to reveal the mechanical features of soil and retaining structures. The results show that the interface slippage between soil and retaining structures is significant and the local sliding failure appears because extreme shear strain of is very small. The influence of dismantling temporary shoring on mechanical and deformation is significant, so it should be fully considered during design and construction of foundation. Time effect obviously exists in the soft soil foundation excavation, so it can decrease the exposure time of excavation and quickly construct the concrete cushion and bottom slab to control the deformation and internal forces of the retaining structures.