WATER AND SOIL PRESSURE CALCULATION METHOD FOR DEEP FOUNDATION PIT WITH SUSPENDED WATERPROOF CURTAIN IN WATER-RICH SANDY COBBLE STRATUM

Abstract

The water and soil pressure acting on the enclosing structure of a deep foundation pit with a suspended waterproof curtain was studied. Assuming a linear variation of the hydraulic gradient from the bottom of the waterproof curtain to the top of the impermeable layer, a two-dimensional steady-state seepage model was established. The solution for the water head distribution at any point in the seepage field of the foundation pit was obtained using the method of separation of variables. A calculation method for water and soil pressure considering seepage effects was proposed. The verification results indicate that the method proposed in this paper yields a 26.8% larger maximum horizontal displacement of the supporting piles and a 5.2% larger maximum axial force in the internal support compared to the measured values. Furthermore, compared to the classical method, the results of this method are 13.9% and 11.2% lower for these values, respectively. This study fills the gap in the theory of non-complete well seepage and its coupled analysis with water-soil pressure, providing a theoretical breakthrough for the precise design and safety control of deep foundation pits in water-rich strata. The proposed method offers more accurate calculations of key parameters than the classical method, providing a valuable reference for engineering applications and demonstrating practical value.