Study on Reasonable Level of Roof Low Level Drainage Roadway in Sijiazhuang 15106 Working Face

Abstract

In order to solve the problem of easy accumulation of corner gas in 15106 working face of Sijiazhuang Mine, based on the “O” ring theory of overburden rock damage, a method of arranging low-level drainage lanes on the roof was proposed. Based on similar model experiments and theoretical calculations, it is obtained that the fracture zone of the “O” ring delaminated zone is 0-20 m on the mining side. The position of the low-level drainage lane should be 5-9 m from the roof of the working face, and within the return air lane. The offset is 0.8-21.5 m. FLUENT simulation results show that the drainage effect is the best when the low-level drainage lane is at a vertical distance of 7-9 m and an internal offset of 3-9 m. In order to facilitate the implementation of downhole drilling, the layout of the low-level drainage lane was set at a vertical distance of 7.2 m, and the offset distance from the return air lane was 5.1 m. At the beginning of the mining, because the large cracks have not yet formed, the gas concentration at the upper corner is dangerous after normal drainage, the gas flow in the low-level and high-drainage lane is about 34.7 m3 /min, and the gas concentration in the upper corner is stable at 0.47%, which meets the requirements of the regulations and solves the problem of gas accumulation in the upper corner.

Keywords

• gas drainage
• upper corner
• similar experiment
• numerical simulation
• low drainage roadway