Application of hollow grouted anchor cable in coal roadway of compound roof

摘要

With the increasing scale of coal mining, the deterioration of engineering geology condition brings great difficulty to roadway support. Main return way 5104 is coal roadway of the loose and cracked compound roof in Zhaozhuang coal mine, the compound roof is difficult to control by using traditional support measures which increase the walls shrink and the floor heave and greatly affect the normal excavation and safe production, or even initiated roof fall accident. Through methods of laboratory tests and field observation, based on the analysis of mineral composition, physical mechanics parameters and development degree of joint fissures, comprehensive analysed the mechanism of the road deformation and failure; expounded the supporting mechanism of the coal roadway with compound roof by means of numerical simulation and theoretical analysis, and proposed the design scheme of combined support of anchor net beam and hollow grouting anchor cable. The industrial test showed that, it achieved the integration of anchor injection by hollow grouting anchor cable, compared to the original support, roof convergence of the roadway is reduced by 76.3%, floor heave value of the roadway is reduced by 45.5%, two nearer quantity of the roadway is reduced by 79.2%, and achieved good results.