Drainage-induced ground response in a twin-tunnel system through analytical prediction over the seepage field

Abstract Leakage-induced hydraulic and ground responses in a twin-tunnel system are analyzed via the proposed analytical solution on the seepage field. The seepage continuity conditions are rigorously satisfied at the interface between the ground and the tunnel lining, in terms of both water pressure and seepage velocity. The analytical solution is verified by comparing the results of numerical simulations. A detailed parametric analysis is carried out to explore the effect of tunnels’ spatial layouts and degraded waterproof facilities on leakage-induced hydraulic and ground response, including head decline, water inflow and ground surface settlement. Our results show that the often used single tunnel model tends to overestimate the pore pressure on the lining along with water inflow into the tunnel, and underestimate the leakage-induced ground settlement.