Research on technology of roadway protection by hard roof-cutting and pressure-relief in fully mechanized caving faces
Aiming at the problem of deformation and failure of the track roadway in the mining area caused by the mining of No.10-205 hard roof fully mechanized caving face in Jincheng Mine,the method of combining theoretical analysis,numerical simulation and field test was used to study the roof cutting and pressure relief roadway protection technology of hard roof.The results showed that the pressure relief effect of the original blasting roof cutting scheme was poor.The fundamental reason was that the height of the roof cutting was too small to effectively block the stress transfer of the overlying strata.The optimization parameters of blasting roof cutting of hard roof in 10-205 working face were analyzed and put forward,that was,the height of roof cutting was 22.6 m and the angle of roof cutting was 12 °.The engineering application of deep and shallow hole combined blasting roof cutting and pressure relief technology was carried out.The roof and floor convergence of the track roadway in the mining area decreased from 856 mm to 315 mm,and the convergence of the two sides decreased from 625 mm to 275 mm.The deformation of the roadway had been effectively controlled and good roadway protection effect has been achieved.
hard roofcutting roof and pressure-reliefroadway protectionstress concentration