Research On Surrounding Rock Control Technology For Roadway Driving Along Goaf Of 414110 Working Face In Shuangxin Mining Industry

Based on the Auxiliary transport chute in 414110 working face in Shuangxin Mining Industry as the research background,the mechanics experiments,theoretical calculation and numerical simulation were adapted for the problem that big coal pillar causing resources waste and stress concentration,and put forward the method using driving along goaf with small coal pillars between the two working face of the 41 mining roadway,studied change rules of the surrounding rock stress distribution and deformation and plastic zone development of different size coal pillars on the chute excavation and the mining in 414110 mining face of,analyzed the influence of different rock parameters on the stability of the surrounding rock,put forward the concrete roadway surrounding rock supporting plan,so as to effectively control the deformation of the surrounding rock,and the following conclusions are drawn:(1)Through field investigation,sampling and laboratory experiments on the mechanical properties of coal and rock samples,the physical property parameters of surrounding rock are measured,which provide mechanical basis for studying the width of small coal pillar and the control technology of roadway surrounding rock.(2)Based on the theory of coal pillar width,the width of small coal pillar is calculated to be 9.81 m.Using FLAC3 D numerical simulation software,the lateral abutment stress of the working face in the upper section is studied,and the position of the peak value of the lateral abutment stress is about 19 m away from the coal wall in the goaf is obtained.(3)Through establishing 3-dimensional mechanical model,the surrounding rock stress distribution,deformation and surrounding rock features in plastic zone in different coal pillar sizes during the excavation in the 414110 li auxiliary transport chute and the mining period of414110 working face have been studied,in combination with theoretical calculation of the coal pillar width and the geological conditions of the actual production,eventually identified that the coal pillar width along the roadway goaf between 414110 working face and the upper section of 414109 working face is 10 m.(4)Based on the theory of natural balance arch,the damage range to the surrounding rock mass after excavation is calculated,and on this basis,the concrete support scheme of anchor cable is further analyzed in theory.(5)Using FLAC3 D to carry out the numerical simulation to calculate the length,spacing,preload and row spacing of different bolts,the influence characteristics to the roadway surrounding rock mass are obtained.Aiming at the problem that the rock mass around the roof of the tunnel is weak,the combined support method of "anchor net cable + steel belt" is put forward,and the support scheme of 414110 auxiliary transportation tunnel is determined by combining with the theoretical calculation of anchor cable parameters.(6)Site industrial test included monitoring the surface displacement of the test section along the trough,small roof abscission layer and fracture of coal pillar.And the results show that the fracture is not sufficient,coal pillar roadway is stable on the whole,the roadway surrounding rock mass deformation is small,all in the range of allowable deformation.The supporting plan have effectively controlled the deformation of roadway surrounding rock,achieving good social and economic benefits.There are 50 pictures,8 tables and 82 references in this paper.