Analysis Of Varing Vertical Shear Modulus In Layers And Transversely Isotropic Layered Soil-foundation Interaction

A rational choice of the foundation model is a very important issue in interactive analysis. Not only that it has a direct impact on the spread and settlement of soil reaction (base pressure), but it also affects the internal force and deformation of the foundation and superstructure. With the development of modern engineering construction, to carry out calculation models systematically for different foundations puts forward higher requirements on the theoretical study of superstructure, foundation and pile-soil interaction.In the actual project, the nature of the soil layer is not uniform, but varies with horizontal and vertical direction. Based on the foundation of the existing layered transversely isotropic and elastic half-space soil model, this paper makes a further improvement, taking account of the non-uniform nature in that vertical shear modulus of soil at every level changes nonlinearly and linearly with the soil depth to respond to the actual soil. Finite layer method is used to deduce the layer element stiffness matrix of layered non-homogeneous soil whose vertical shear modulus varies with depth following the exponential law and those varies with depth following the linear law.On the basis, The paper explores the effect regulation of the improved foundations model to the rigid cap-piles-soil nonlinear interaction. In the research practice, neglecting pile-pile and pile-soil interaction this minor factor, but reflecting the complicated pile-soil nonlinear interaction with the single pile's nonlinear phenomenon. While the description of the single pile's nonlinear is based on the simplified static load test information. By the example which combined with engineering analyzing, The paper study the rigid pile cap and pile-soil interaction with different pile amount and different pile spacing condition, and makes out the changing curve pictures of certain parameters, like load sharing ratio of soil, average settlement of foundation base .etc which is concerned especially in engineering. The study shows that, when the pile amount is small or when using the natural foundation, the foundation model which the layer shear modulus varies with the depth has a great impact on foundation settlement. It is indicated that if we do not consider certain design in actual project, it may turn to insecurity.This article has also studied the situation when the surface existence hard shell, The result indicates load sharing ratio of soil between piles increased obviously, and the settlement of cap reduced obviously. Therefore, matting some thickness crushed rock layer under the bottom of cap and compact properly may enhance greatly the bearing capacity.