Roadway Support Technology for Upward Mining of Soft and Broken Surrounding Rocks in Western Mining Area

QinHua Coal Mine is located at the southwest edge of Yanqi Basin, Korla City,which main coal seam group spacing is close, and the interlayer rock strata is soft and broken. Affected by the upward mining, it is difficult to support the mining roadway of the upper coal seam. The FLAC3D numerical model is established to analyze the effect and influence area of the lower coal seam recovery support pressure on the upper coal seam, determine the reasonable position of the mining roadway under the upward mining conditions, and optimize the roadway support scheme. The study shows that the upper cover coal seam mining roadway of Qinhua coal mine should be arranged in the internal wrong type, and the internal error of 4-8m is appropriate. When the full anchor cable is supported on the top of the roadway, the stress concentration coefficient and plastic damage range of the roadway are small, which promotes the peripheral stress peak of the roadway arch area to the depth of the surrounding rock and improves the stress environment of the shallow surrounding rock of the roadway. The roadway arch adopts full anchor cable support. Compared with the simple bolt-anchor cable support structure, it has the advantages of wide range, large support strength and good support effect. In the support system of the roadway under the loose broken surrounding rock, a full anchor cable support system should be established in the roof rock layer of the roadway.