Comprehensive technology to find lining seepage water passage ways of a highway tunnel in Karst areas of China

Most of Chinese existing tunnels are faced with water disasters to some extent, of which leakage and derivative hazards of operating expressway tunnels are the commonest. If causes for leakage in liner can be learned, the treatment of the leakage-incurred water disasters of tunnels during the tunnel service can have rules to follow. This paper employs multi-electrode resistivity method to probe and conduct cross section analysis of major parts of tunnels, and generally outlines the karst leakage passages in major areas of Pishuang'ao Tunnel. Then, tracer experiment is conducted to explore the connectivity between multiple subsides and Pishuang'ao tunnel. The results of tracer experiment and multi-electrode resistivity method are mutually verified, and the corresponding relation among the collapses, karst cave and surface water infiltration points and the relevant discharge areas is obtained. All these findings can provide the scientific basis for treatment of leakage in Pishuang'ao Tunnel.