Numerical Analysis of Deformation Effect on Adjacent Piles Due to Excavation

Combined with the project of an open cut metro tunnel passing through a viaduct, three- dimensional finite element method is applied to study the lateral deformation law of viaduct pile foundations induced by adjacent excavation in the pile foundations reinforcement and un-reinforcement conditions. The results show that the lateral deformation of pile foundations increases with the increasing of excavation depth. The closer distance and the larger deformation, the influence of pile foundations on excavation will be more obvious. The pile foundations deformation is significantly reduced when taking protection measures such as adding new piles, expanding the pile cap and strengthening stratum. Compared with the maximum deformation of the un-reinforcement condition, the reinforcement condition is only 27% to 30%, and the reinforcement measure is remarkably effective. In addition, the length of the piles, the depth of foundation pit, as well as the relative positions of walls and piles have significant influences on piles deformation forms, and it should be taken into account in the design and construction of foundation pit.