Effect of excavation on piles

ABAQUS is a popular commercial finite element software and the clay plasticity model presented in it can perfectly simulate the stress-strain behavior of the normally consolidated clay. A three-dimensional finite model is established in ABAQUS to study the deep excavation effect on the underpinning piles which are constructed before the soil excavation. The parameters employed by the porous elasticity model and the critical state plasticity model in ABAQUS are decided according to the triaxial compression tests or oedometer tests. To verify the numerical simulation results, the initial void ratio obtained from the programmed subroutine and the deformations due to the soil excavation are analyzed. The variation of the axial forces with the soil excavation is presented. The distribution of the axial forces and bending moments for the piles at different locations can be obtained from the numerical simulation results. The regularities of distribution for the forces and moments are discussed and the influence factors are also mentioned. The results obtained here can be referred for similar practices.