Elastoplastic solution for excavation-pile interaction

Based on the elastic theory method and p-y curve method,the elastoplastic solutions for the problem of excavation adjacent to the existing pile foundations were given.The solution utilized the sliding interface element between soil and piles and the uniform limiting soil-pile interaction force to consider plastic yield of soil.In the solution,the pile foundation was regarded as one-dimensional bar structure and its interaction with the soil was realized through spring and sliding interface element.When the soil was in elastic state,the deformations of pile and soil were coordinated and the sliding element didn’t work.When the soil stress reached the limiting value,the plastic deformation appeared in the soil and the sliding element was acted under the limiting force and plastic sliding occurred at the same time.In the calculation,Young’s modulus of p-y curves of soil layers varied with the soil displacement,so the interaction between the piles and soil was nonlinear.It was indicated by analysis of example that the calculated results of the elastoplastic solution were reasonable and could be used to analyze the problem of excavation adjacent to pile foundations.