Deformation of deep foundation pits due to excavation considering change of void ratio and permeability coefficient with depth

Based on the effect of fluid-solid coupling, the subroutine is complied by using the user subroutine named VOIDRI of ABAQUS to achieve the void ratio nonlinearly changing with depth. Meanwhile, the coefficient of permeability changing with depth is set. According to the comparative analysis considering or ignoring the effect of fluid-solid coupling, many useful conclusions are drawn. The position of the maximum horizontal displacement of wall at each excavation step changes with the excavation depth and different supporting situations. The ground settlement considering the effect of fluid-solid coupling is greater than that ignoring the effect of fluid-solid coupling. The rebound at the bottom can significantly decrease due to the effect of fluid-solid coupling. However, the horizontal displacement of surface is less affected by fluid-solid coupling. As a result, these conclusions can be used as an important reference for predicting the deformation of foundation and supporting structure during excavation of deep pits.