Numerical Analysis of the Installation Process of Screw Piles Based on the FEM-SPH Coupling Method

Abstract

The installation of screw piles can cause damage to the soil, which is a dynamic and large deformation problem. In this paper, a FEM-SPH numerical model for the analysis of this large deformation problem was developed in LS-DYNA to simulate the installation process of screw piles. In addition, field installation tests of screw piles were carried out. By comparing the FEM-SPH simulation results with the experimental results and traditional FEM simulation results, it was found that the FEM-SPH coupling method has higher efficiency and accuracy in dealing with the large deformation problems caused by the installation of screw piles. Then, numerical simulations of screw piles with various parameters were conducted to analyze the differences in the installation process. The results show that the spiral pitch and pile diameter have a significant effect on the installation torque, soil stress and soil pressure during the installation process. During the installation process, the interaction between the screw pile and the soil is transferable. The installation of the screw pile will lead to the movement of soil particles in the radial and axial directions, resulting in heave damage to the shallow soil and cylindrical shear damage to the middle and deep soil. The influence range on the soil by the heave failure mechanism (HFM) and the cylindrical shear failure mechanism (CSFM) caused by the installation of screw piles is affected by pile parameters. The change in pile diameter will act on both HFM and CSFM, whereas the variation in spiral pitch will only have an influence on CSFM.