Study On Supporting Technology Of Shaft Bottom At -420m Level In The Ninth Mine Of Hebi

The ninth mine owned to Hebi Coal Group went into operation in the fifties and sixties last century,and have reached deep mining. But the way of rock workings support still uses bolting-shotcreting support,U-shed support, or bolting-shotcreting and U-shed combined support. Surrounding rock failure phenomenon in deep roadway appeared in the ninth mine such as side falling, puking, large deformation of surrounding rock, large stress and so on in deep roadway of new auxiliary shaft. The existing support methods could not adapt to the deformation of surrounding rock in deep roadway, and some was crushed shortly afterward, and even fractured in the tunneling process, which affected the normal production of the ninth mine seriously.Aiming at -420m level new auxiliary shaft bottom which in the ninth mine, utilizing investigate analysis, deformation monitoring and numerical simulation methods, studies have been done in the thesis as follows:1.Through the engineering geological studies of shaft station, engineering geological rock groups were classified;according to the geological data in the Hebi mines, the distribution of stress field of the ninth mine's shaft station was determined.2.The breaking reason for the -420m level new auxiliary shaft of the ninth coal mine was invested, the nature of the shaft station's roadway engineering and testing roadway deformation mechanics mechanisms were determined, the main reason of identifying new auxiliary shaft mine-420m level roadway deformation destruction was found out for supporting development of the correct measures. The application of bolt and mesh reinforcement and high-convex strip and anchor wire and base angle bolt coupling support, successfully resolved the problem of stability control of the nine mine-420m level of roadway.3. By theoretical analysis and numerical analysis to two kinds of absorbing well system of absorbing well group and intensive absorbing well, intensive design idea of the new auxiliary shaft -420m pump room system design was determined. Practice has shown that intensive designs are not only successful, but also achieved remarkable economic benefits, and also playing the role of science demonstrations for Hebi mine pump room system's design and construction under the critical depth. 4. Through three-dimensional numerical simulation analysis to roadway engineering effects of main tunnel angle in an intersection, the conclusion was produced that the main roadway should be constructed firstly, and then the branch roadway,and 90°is the better angle between main roadway and branch roadway in the construction of cross roadways of constant section. At the same time the reinforce ideas and methods of "Y"-shaped intersection were given.5. During construction process of the trial tunnel, the information-based construction method was carried out for the timely monitoring deformation and feedback design. According to monitored information in substations and pumping stations and predicted information in sump, support parameters of mine sump were optimized.