Study On Deformation Mechanism And Control Of Roadway Driving Along Next Goaf Full Seam Mining In Thick Coal Seam

In this paper,we take roadway driving along next goaf full seam mining of thick coal seam in the Fucun Coal Mine as the research object.By theoretical analysis,field test and numerical simulation,the failure characteristics of surrounding rock in roadway driving along goaf with full height mining at thick coal seam are studied.On the basis of this,the optimization scheme of bolt support suitable for mining full height along goaf in thick coal seam is determined and applied to field practice to achieve efficient and the efficient and safe coal recovery having been realized.Through field measurement,the distribution rule,peak position and low stress range of the abutment pressure of fully mechanized coal face are obtained.On this basis,through the comparison and analysis of the stress numerical simulation of the surrounding rock of different coal pillar sizes,the rational retention width of the small coal pillar in the gob roadway is determined to be 5m.In order to avoid the significant influence of the violent movement of the basic top and alleviate the abnormal tension between mining and driving,through the measurement and analysis of surrounding rock deformation of the gob side entry roadway in the thick coal seam of the Fucun Coal Mine.The time of roadway driving along the goaf should not be less than 46 days.With the numerical simulation method,the influence of different factors such as the depth of coal seam,the size of the section and the thickness of coal seam on the distribution of surrounding rock and displacement is analyzed,and the influence of different factors on the deformation and failure characteristics of the surrounding rock is further explored.Through the field measurement,the influence range of the advance support pressure caused by the working face recovery is determined,and the deformation and failure characteristics of the surrounding rock of the thick coal seam with full height along the goaf are clarified,mainly including the relatively broken surrounding rock,the poor integrity and integrity of the roadway surrounding rock,and the low stiffness of the rock mass within the anchorage range.The main reasons for the deformation and failure of the surrounding rock are revealed,such as the complex stress environment in the roadway surrounding rock,the unreasonable selection of roadway support parameters,the unreasonable selection of the bolt supporting component and the large size of the tunnel section.In view of the deformation and failure characteristics of the surrounding rock of full high seam roadway excavated in thick coal seam and the actual situation of Fucun Coal Mine,the Countermeasures of surrounding rock control are put forward,which are "improve anchor pre tightening force+high strength steel belt+strengthen weak position",and applied to the production practice of 1008 working face along goaf.The field application results show that the deformation of the roadway surrounding rock is greatly reduced after the optimization scheme,the control effect of the roadway surrounding rock meets the normal production requirements of the working face,and effectively solves the problem of the difficulty of supporting the thick coal seam with the full height along the empty roadway in the coal mine of Fucun Coal Mine.The research results in this paper have a good reference and promotion value for bolt support in gob side entry under similar conditions.