Research On Failure Characteristics And Control Of Floor Heave In Multiple-seam Repeated Mining Of Faer Coal Mine

In the joint mining of coal seam group,because of the influence of repeated mining of coal seam,the centralized roadway presents the characteristics of continuous rheology,so it has to be repaired many times to meet the needs of mine safety production.Therefore,the systematic analysis of the deformation and failure mechanism of the floor heave of the centralized roadway under the condition of multiple coal seam repeated mining has certain theoretical guidance and engineering practice significance for the floor heave control technology of the centralized roadway under the combined mining of multiple coal seams.In this paper,based on the engineering background of the failure section of the floor heave of the centralized track roadway in the faer coal mine,the deformation and failure characteristics of the roadway floor are measured,the composite failure mechanism of the overburden structure of the multi seam combined mining is studied,and the control technology of the floor heave of the multi seam repeated mining roadway is proposed,and the following research results are obtained:(1)In this paper,the characteristics of the floor heave of the centralized track roadway are measured,and the factors of the floor heave deformation are analyzed.The composite failure model of the overburden under the influence of the repeated mining of multiple coal seams is established,which reveals the mechanical transfer of one side of the repeated mining coal pillars and the deformation and failure mechanism of the roadway floor under the pillars.(2)The composite fracture characteristics and migration law of overlying rock structure under the influence of repeated mining in multi-coal seam are studied by numerical calculation,and the stress distribution of surrounding rock of concentrated track roadway and the temporal and spatial evolution of bottom heave are grasped.It is found that 1 coal and 5-3 coal mining have little effect on the stability of roadway floor,while 3 coal,5-2 coal and 7 coal mining show continuous Rheological characteristics.(3)According to the above research results,the control scheme of surrounding rock floor heave in different stages is put forward,and the stress distribution of surrounding rock is studied by numerical method.Combined with field construction and production requirements,the optimization scheme and reasonable parameters of floor heave control for centralized track roadway are proposed.(4)The industrial test shows that the tunnel floor heave is effectively controlled under the conditions of excavation of pressure relief groove at the north side of the tunnel with a depth of 2m and a width of 0.8m,excavation of pressure relief groove at the south side with a depth of 2.5m and a width of 1.0m,backfilling of gangue,grouting of surrounding rock of the tunnel and anchor support at the bottom angle.This thesis includes 80 Pictures,7 Tables,and 89 References.