Analyses of the effect of deep excavation on behaviour of adjacent pile in sand using 3D finite element method

The influation of deep excavation on adjacent pile behaviour is an important issue to ensure its serviceability and stability. In this paper, the effect of deep excavation on an adjacent loaded single pile in saturated cohesionless soil was investigated by 3D finite element method. After verification of finite element model using centrifuge test results found in literature, a parametric study was conducted by varying the most influence factors on pile behaviour such as excavation depth, distance from pile to the excavation and pile head type. It was concluded that the excavation depth with respect to pile length has a significant effect on pile response. Among the three cases of H_e/L_p, the case of H_e/L_p= 0.5 induced the maximum bending moment while the case of H_e/L_p= 1.5 induced the maximum pile lateral deflection. Moreover, the distance from the pile to the excavation site has also a significant influence on pile response and the induced bending moment in pile is inconsiderable after 9 m distance. Also, it is observed that the pile head type has an important effect on the pile behaviour especially in case of rigid head case. Both increasing the working load applied on pile and increasing the pile length do not have a significant effect on the lateral behavior of pile.