The Safety Analysis on External Water Pressure to the Deep Buried Hydraulic Tunnel Lining Based on Coupling Numerical Simulation

Abstract The high external water infiltration pressure of deep buried hydraulic tunnel frequently causes damage to lining structure. The safety analysis on high external water pressure to the lining of deep buried hydraulic tunnel becomes critical work. The stress and seepage coupling interface model is established to simulate the influence of external water pressure on the safety of deep buried hydraulic tunnel lining by means of sensitivity analysis of three parameters including grouting thickness, permeability coefficient of grouting area and the depth of drainage hole. It turns out that the external water pressure decreases with the increase of grouting thickness and the depth of the drainage hole into rock while permeability coefficient shows less effects on it. A series of highly applicable designs are provided aiming to improve the safety of deep buried hydraulic tunnel lining.