Research And Application Of Settlement Theory On Bridge Rigid Pile Composite Foundation

In this paper, the modified Cam-clay model and Mohr-Coulomb model (as a comparison model) have been employed to simulate the elastic-plastic behavior of soil. Aslo the Biot consolidation theory as the basis of the caculation. Using ABAQUS finite element analysis, the author studied the stress changes, the displacement of soil, the consolidation of the soil, time-history curve of the settlement and the dissipation of excess pore pressure.The study on dissipation of excess pore pressure suggest that the dissipation of excess pore pressure in the consolidation process can be divided into two phases:①Local diffusion stage, at this stage the dissipation of excess pore pressure of soil around bottom of pile is similar to ball expansion, while, the dissipation of excess pore pressure of soil, around pile side, which caused by friction is Similar to the cylindrical cone expansion. Contrast the settlement time-history curve shows that the influence of consolidation settlement is bigger in this stage.②After the local diffusion stage, the dissipation of excess pore pressure of soil turns to vertical, while, the influence of consolidation settlement becomes less, because excess pore pressure becomes smaller.The research on soil horizontal displacement shows that:excess pore pressure is dissipating outward, and soil is shrinking close to pile.