A formula for hydrostatic pressure calculation in high-pressure railway tunnels

High hydrostatic pressure can cause common problems such as cracking and leakage in the lining of railway tunnels during operation. A clear understanding of the magnitude and distribution characteristics of hydrostatic pressure in tunnel lining under high-pressure conditions is crucial for optimizing the structural design of tunnel lining. In this study, professional equipment was first selected to measure the lining water pressure of two typical sections of Tunnel A on site, and the pressure distribution characteristics were analyzed; Then, a calculation model of the tunnel under high hydrostatic pressure was established using FLAC3D numerical calculation software. Select several calculation parameters and within a reasonable range of values, select multiple values for each parameter instead of just taking one value to form 60 working conditions, and calculate the corresponding tunnel lining water pressure for each working condition. Analyze the correlation between static water pressure and calculation parameters under various working conditions, propose a preliminary calculation formula for tunnel lining static water pressure, and finally use SPSS statistical calculation software to fit the final calculation formula for lining water pressure. This formula is applicable to the calculation of lining hydrostatic pressure under various parameters and is a universal calculation formula for tunnel lining hydrostatic pressure. Our proposed formula is very consistent with on-site measured data under similar geology conditions, providing a new method for calculating the hydrostatic pressure of tunnel lining.