关键词: 多层地基, 软土, 荷载传递法, 沉降计算, p-y曲线法, 有限差分法

Abstract: According to the physical and mechanical properties of foundation soil in the area of deep multilayer soft soil, a new pile-side and pile-end model is adopted to simulate the load transfer mechanism of a single pile by considering the initial ultimate shear stress of pile-side soil at low-load level, the stress softening characteristics at high-load level and the piecewise performance characteristics of pile-end soil bearing capacity. Based on the above model, the iterative method can be applied to calculate the settlement of the single pile top, the axial force of the pile body and the pile side resistance. The p-y curve, which is easy to obtain and suitable for soft soil, is used to describe the nonlinear relationship between pile-soil interface force and displacement. Based on the Euler-Bernoulli beam and centre difference theory, a numerical calculation method is conducted by considering the boundary conditions of the pile tip. The rotation angle, shear force and bending moment of the pile along the length direction are calculated to obtain the variation characteristics of these variables under a specific load. Finally, as verified by an engineering case, the calculation of the above method is simple and in good agreement with the actual testing results.

Key words: multi-layered foundation, soft soil, load transfer method, settlement calculation, p-y curve method, finite difference method