A numerical study on ground displacement and stress during and after the installation of deep circular diaphragm walls and soil excavation

摘要

Three-dimensional total stress elasto-plastic FEM analysis was conducted to examine ground movement and stress after the installation of circular diaphragm walls and soil excavation within the walls. Combinations involving three different wall thicknesses and two different excavation sequences within the wall were adopted to investigate differences in the final ground movement and the lateral stress in the ground after wall installation and excavation within the wall in multi-layered ground. The analysis results showed that the construction sequence significantly affects ground displacement and lateral stress behind the wall, implying that the situation even before excavation within the wall is no longer axisymmetric. Reducing the wall thickness also reduced the vertical and circumferential section forces of the wall after excavation within it.