Study On The Formation Mechanism And Control Measures Of The Leakage Water In Unlined Highway Tunnel

In the early highway construction, as lacking funds and short period ,resulting in many highway tunnels built without timely support, formed a " unlined tunnel", or "bare hole tunnel." As part of the highway tunnel has been built for many years without lining, and no lining protection, over time, due to geologic, climatic conditions and the design, construction and operation of various factors, during the tunnel process in the long-term use appears in a variety of different levels of disease. According to Chongqing Municipal Bureau of Transportation statistics show that the quantity of tunnels on Chongqing national and provincial line is 175, a total of 97415m,State Road 115, a total of 71755.7m; Provincial Highway 60, a total of 25659.3m. Thereinto crisis tunnel is 51, on the national highway 45, on the provincial highway 8, a total of 14408m,which is 14.79% length of all the national and provincial Chongqing tunnel (97415m) .In this 51 crisis tunnel,there are 43 bare hole tunnel. The crisis tunnel disease mainly performance as follows: 1, rock start loose, blocked, and even deformation in the long term effect of stress concentration and weathering,; 2, there are dripping, water seepage and a large area of infiltration in the tunnel; 3, As the poor drainage system and other reasons in the tunnel, result in a badly damaged of the pavement. Among them, the most common and serious disease is water damage .So researching the mechanism of water damage of unlined tunnel and how to control it is very necessary.This article selects the White Horse tunnel and Great River tunnel as the objects of study ,whose leakage water is more serious than other tunnels on the national highway 319. With a field investigation of the White Horse tunnel and Great River tunnel, we sum up the the main forms of leakage water and analyze the influence of leakage water doing with the operating unlined tunnel . Adopt rainfall infiltration method, ground runoff modulus method and underground runoff coefficient method to calculate the quantity of seepage water of the White Horse tunnel.From the geological structure , geomorphology, lithology and hydrogeological four aspects ,the thesis analysis the formation mechanism of the leakage water of bare hole tunnel .Adopt the FLAC software to simulate the influnce of the underground under a different level to the surrounding of bare role tunnel on displacement, stress, the water pressure and plastic zone and other mechanical properties. For the main forms of the leakage water of bare role tunnels on State Highway 319 ,combined with control measure of lining tunnel, developed a set of waterproof and drainage measure of bare role tunnels . Combined the special situation of State Road 319 and the latest controling leakage water material, and according to the different types of surrounding rock, the thesis set down the prebentive and control measures of bare role tunnel on the State Road 319 .