Optimization of Collaborative Support for Retaining Roadway Along Goaf and Roof Cutting Pressure Relief in Coal Seams with Large Inclination Angle

In view of the difficult problem of controlling the surrounding rock of the retaining roadway along goaf in coal seams with large inclination angle, taking a working face with large inclination angle coal seam in Guxian Lanhua Baoxin Coal Industry Co., Ltd. in Linfen, Shanxi Province as the background, a high-pressure hydraulic fracturing roof cutting and pressure relief collaborative support optimization scheme is proposed. The cutting parameters are optimized by FLAC^3D numerical simulation, and a three-dimensional support system is constructed by combining Ф22 mm high-strength anchor cable, 36U type steel retractable bracket, and grouting reinforcement. The on-site application shows that the maximum roof subsidence amount is decreased from 327 mm to 72 mm, the heaving floor is reduced from 156 mm to 43 mm, the load uniformity of anchor cable is improved by 61.8%, and the support cost is reduced by 17.9%. The research results provide technical references for the design of roadway support with similar conditions.