Study on “unloading-support-protection” technology of gob-side entry in high gas working face in Western Guizhou

In order to solve the problem that the effect of gob-side entry in high gas working face in Western Guizhou is not ideal, taking 1404 working face of Xintian Coal Mine as the engineering background, this paper puts forward the “unloading-support-protection” technology and its specific content.According to the numerical simulation of different parameters of gob-side entry, the optimal parameters suitable for gob-side entry in 1404 working face are obtained through comprehensive analysis.Based on the simulation results, an industrial test is carried out in the working face, and continuous monitoring is carried out to verify that the application effect of “unloading-support-protection” technology is good.The results show that under the joint action of the three, the “unloading-support-protection” technology of gob-side entry effectively controls the deformation of roadway, and the effect of retaining roadway is good.The effect of roof cutting and roadway retaining can be effectively improved by determining the appropriate roof cutting angle and the width of flexible mold bag and determining the drilling depth of roof cutting according to the situation of roof.The field observation results show that the maximum approach of the roof and floor of the reserved roadway is 414.0 mm, and the maximum approach of the two sides is 211.4 mm.The roadway deformation is controllable, which can meet the use requirements in the later stage of the reserved roadway.The research shows that the “unloading-support-protection” technology can effectively cut the roof and relieve the pressure and bear the roof deformation, so as to effectively control the roadway deformation of the gob-side entry, ensure the normal use of the retaining roadway and reduce the later maintenance cost.