To mitigate water leakage problems in high-pressure tunnels and lower the costs associated with remediation,a novel limited drainage approach is proposed,utilizing a double-bonded sprayed waterproofing membrane.This approach comprises three components:grouting circle,double-bonded waterproof drainage system,and waterproof lining.The water pressure distribution characteristics of this novel limited drainage method are elucidated through numerical calculations,demonstrating its efficacy.Additionally,an analysis is conducted to assess the impact of various grouting circle and drainage sheet parameters on tunnel water inflow and lining water pressure.This analysis presents a design methodology for a multistage limited drainage scheme for high-pressure tunnels.The findings indicate that the novel limited drainage scheme can effectively reduce secondary lining water pressure to an acceptable level by adjusting the grouting circle and drainage sheet parameters.Unlike conventional high-pressure tunnel designs that predominantly rely on grouting circles for regulating seepage and lining water pressure,the proposed drainage-limiting scheme employs a multistage control approach involving both grouting circles and drainage sheets,offering enhanced flexibility in scheme design,with the grouting circle assuming a pivotal role.The grouting circle proves advantageous in minimizing tunnel seepage and external water pressure on the lining,with particular emphasis on the permeability coefficient parameter.Ensuring an appropriate permeability coefficient for the grouting circle allows for establishing reasonable spacing between drainage sheets,effectively managing lining water pressure and tunnel seepage within acceptable limits.These research outcomes can serve as valuable guidance for the design of drainage systems in high-pressure tunnels.
high water pressure tunneldouble-bonded waterproofing materiallimited drainagesprayed waterproofing membraneseepage analysis