Research On The Stability Of Xikouchi Tunnel Through The Coal Mine Gob

The route area of Xikouchi tunnel is situated at the eastern of Sichuan Basin in the third depression area of Neocathaysian . Folding is the main geological structure in this area,and the rollability is huge.The geomorphic unit is the low mountains physiognomy of tectonic denudation. The main strata of the tunnel area are stone mingled with carbonaceous mudstone,coal and mudstone mingled with argillaceous limestone,and the tunnel area cuts across the collecting spece area of Jinfu Coal Mine and Maanchun Coal Mine. Because of a wide range of the coal mining collecting spece area distribution, the mass of rock in collecting spece area is repeatedly affected by mining, the rock body is more broken and the original structure was severely damaged. With the coal mining method for the longwall mining method, waste rock backfilling the mined areas, roof caving naturely, the current state of mined areas is half-filling,where found no ground deformation and subsidence, there are greater residual deformation on surface.These would have a greater impact on the security of the tunnel construction and operation.In this paper, the section of Xikouchi tunnel acrossing the collecting spece area of coal mine is studied.By analyzing the geological and mining characteristics of the coal mining area, the movement of mantle rock in the collecting spece area of coal mine and residual deformation on the surface are studied,and the impact of the rock stability in the collecting spece area of coal mine is evaluated.Meanwhile, the deformation law during the tunnel excavation and the negative factors of the location relationship between the collecting spece area and the tunnel are analysed by the FLAC3D software. The existence of mined areas and position affected on the tunnel stability is systematically analysed in this paper. On this basis, the paper also put forward a concrete construction plan for the location between the collecting spece area of coal mine and the tunnel, and aimed at the potential water inflow and gas phenomenon,some management recommendations is provided in this paper.In short, by the above-mentioned research, this article systematically studied the deformation law when Xikouchi tunnel passing through the collecting spece area of coal mine, and thus better able to guide the Xikouchi tunnel construction.It can provide protection for the construction and operational safety of Xikouchi tunnel,at the same time for future similar projects to provide a certain reference value.