Research On Treatment For The Seepage Disease Of Highway Tunnels In Karst Area

In recent years, with the increasing numbers and mileages of highway tunnels year by year, tunnel diseases appear more frequently during the operation process. Among the tunnel diseases, leakage draws a lot of attention because of its wide distribution, high hazard degree and difficult treatment. Hence, it is very urgent to carry out the research on the formation mechanism and treatment measures of the leakage disease.This paper has summarized the common features of the seepage water disease and worked out the reasons based on the highway tunnels where seepage water disease occurs in Chongqing. Formation mechanism is analyzed and measures of treatment are studied with numerical simulation method. Investigation contents and results are as follows:(1) Through the analysis of15operating highway tunnels with severe leakage diseases in Chongqing area, quantitative evaluation of the severity of the tunnel leakage diseases is conducted. The spatiotemporal distribution, as well as the experiential reason of highway tunnel leakage diseases in karst area is summarized.(2) By using the temperature analogy method, water pressure distribution on tunnel linings and safety performance of the supporting structure are analyzed from three aspects: change of groundwater level, hydraulic conductivity effects of karst fissures and deterioration of the tunnel drainage system. Furthermore, the causal mechanism of seepage diseases was then analyzed.(3) Based on the pressure status of tunnel linings, seepage and leakage diseases are divided into two categories:bearing type and non-bearing type. The principle of treatment and corresponding countermeasures are raised taking into account of the spatiotemporal distribution of highway tunnel leakage diseases and causal mechanism of seepage diseases in karst area.