Deformation Failure Mechanism and Control Technology of 6112 Return Air Drift in Haishiwan Coal Mine

In order to solve the problem of large deformation of 6112 working face in return air drift of Haishiwan coal mine No.1 coal seam,the paper studied the deformation mechanism,and proposed two sets of solutions from the aspects of roadway re-arrangement and the optimization of bolting parameters.Field test results showed that after roadway repairing by using the stability control technology of HRB335 high strength anchor withφ18.9 small-bore prestressed anchor cable,the convergence of roof and floor and two sides of return air drift had been effectively controlled,which eliminated the problems of roadway repeated maintenance in the past.