Analytical Solution for Pile Response Due to Excavation-induced Lateral Soil Movement

Abstract

The excavation of foundation pits in building compact district of urban will inevitably bring about the lateral movement of the soil mass surrounding foundation pits to a certain excent, which may generate the additional deflections and bending moments in the adjacent pile shaft, and may lead to their superstructures distress, even failure. In view of the drawbacks of existing numerical method, such as complex modeling and time-consuming, the Two-stage Analysis Method (TSM) is presented to determine the behavior of adjacent pile caused by foundation pit excavation based on Winkler model in this paper. Firstly, the additional lateral displacement distribution of soil mass due to the excavation of adjacent foundation pit and displacement of retaining wall structure is calculated by the virtual image technique. Secondly, the interaction of adjacent pile with the surrounding soil mass is achieved by setting the Winkler spring. Thus, the governing differential equations are built up based on Winkler model and their analytical solution of matrix is derived to analysis the impact of excavation on adjacent pile. Finally, the study of case histories shows that the calculated results of analytical solution are reasonable and the present approach procedure could be used to analyze the influence of excavation on adjacent pile foundations. Generally, it has the very good guidance on the influence of foundation pits excavation on adjacent pile.