Lateral Response of Contiguous Pile Wall Subjected to Staged Excavation: Physical and Numerical Investigations

Abstract

In this paper, the lateral response of a contiguous pile wall retaining system under staged excavation is investigated using physical modelling. The effect of pile stiffness on pile wall deformation is studied by changing the diameter of pile. Numerical simulation of the physical response of the pile wall is studied using the finite element program PLAXIS-3D. Results of the finite element (FE) analysis are in good agreement with the experimental results. Sensitivity analysis is carried out to evaluate the effect of unit weight and friction angle of sand on the lateral response of the pile wall. It is found that with increase in the unit weight of sand, the deformation of pile wall increases and with increase in the friction angle of sand, the deformation of pile wall reduces. Experiments were performed on the sand to evaluate the unit weight, friction angle, Young’s modulus and Poisson’s ratio of sand corresponding to the four different values of the relative density (i.e. Dr = 15, 35, 65 and 85%). The response of the pile wall under stage excavation with change in the relative density of sand is studied by performing FE analysis. It is found that with increase in the relative density of sand, the deformation of pile wall reduces. The interpretation of modulus of elasticity of sand from the modulus of subgrade reaction evaluated from the plate load test is also presented. Based on the results of the FE analysis, it is noted that the finite element method (FEM) can be used for the real-time simulation of the lateral response of the pile wall systems.