Study on surrounding rock control technology of entry retaining by roof cutting with double main roof in inclined soft hard interaction rock

Aiming at the surrounding rock control problem of double basic roof cutting and retaining roadway in inclined soft and hard rock strata, this paper expounds on the comprehensive roadway protection mechanism of goaf side-roof-solid coal side under this geological condition, and puts forward the comprehensive control technology of goaf side “U-shaped steel roof cutting and bottom cutting + high strength anchor cable + metal mesh gangue retaining”, retaining roof “groove steel truss anchor cable + roof cutting anchor cable + single pillar roof”, and solid coal side “groove steel truss anchor cable strong anchoring”. On this basis, the blasting roof cutting parameters such as hole layout form, hole spacing and angle, hole layout depth, charge parameters and sealing mud length are designed. The field results show that the roof cutting hole of about 9.5 m is beneficial to the surrounding rock control of roof cutting and retaining roadway in inclined soft and hard rock strata. The final deformation of the roof and solid coal side of the cutting seam is about 192 mm and 119 mm, which ensures the safe mining of the lower working face.