Research And Application Of Bolt-mesh-cable Support Technology In Complex High-stress Soft Rock Roadway

The stable support technology of high stress soft rock roadway has always been a difficult problem in mine roadway engineering support,especially when the roadway is near fault,and the roadway often presents complicated high stress characteristics because of its complex high stress environment and the coupling action of large buried depth and high stress.At the same time,the serious mine-pressure behaviors of roadway are easy to occur under the complex high stress environment due to the poor integrity and low surrounding rock strength of this kind of soft rock roadway,for example,the coal and rock mass slip along the bedding plane,two sides of splitting failure,the roof subsidence and floor heave.Based on the roadway supporting engineering test in the extension section of auxiliary belt downhill in No.4 mining area of Yangquan coalmine,the bolt-mesh-cable support technology of complex high-stress soft rock roadway is systematically studied.Based on the analysis and research for the geological conditions of the roadway about the extension section of auxiliary track downhill in No.4 mining area,the failure mechanism of complex high stress environment to soft rock roadway support,the deformation mechanism of composite soft rock roof and existing problems of original supporting system have been explored.The deformation mechanism of the roadway about the auxiliary track downhill are explained by means of FLAC3D numerical simulation method and the supporting principle and supporting scheme of anchor-mesh-cable are put forward.The basic support parameters of the experimental roadway is obtained,for example,bolting pre-tightening force,high strength bolting support system and surface supporting design by FLAC3D numerical simulation method;the supporting reform of test roadway is carried out under the premise of standardized supporting material standard and construction standard.The results of mine-pressure monitoring and actual supporting status investigation show that the experimental roadway support reform has been successful in the aspect of roadway stability control,saved the comprehensive cost of roadway support,improved the excavation efficiency,prevented the roadway from returning to repair and achieved good benefits.