High pretensioned stress and intensive cable bolting technology set in full section and application in entry affected by dynamic pressure

The present problems of cable bolting in coal mines were analyzed.Based on high pretensioned stress and intensive bolting theory,it was put forward that the high pretensioned stress and intensive cable bolting with shorter length,set in full section and vertical to surface of roadways is an effective supporting type to the roadways with high stress or large deformation.The mechanical properties of intensive cable bolts,plate and steel mesh were introduced.The full section intensive cable bolting system was formed by intensive cable bolts combined with large domed plates and reinforced steel mesh.The reinforced steel mesh was put higher pretensioned stress when the cable bolts were pretensioned,which became an important part for pretensioned supporting system.The underground experiment of the full section high pretensioned stress and intensive cable bolting was carried out in an entry driven close to a facing working face,which was affected by twice violent dynamic pressure,and essential changes were taken place in entry supporting state.The side-to-side convergence of the entry is reduced about 90% compared with the former supporting type,the roof delamination is reduced to almost zero,and the deformation of the surrounding rock is effectively controlled.The difficult problems of roadway supporting were solved,meanwhile,the validity of the bolting theory was verified.