Study on mechanism and control of separation instability in deep-buried composite roof coal roadway
To explore the separation instability and control mechanism of deep-buried composite roof coal roadway,taking the 1692(1)transport roadway in a mine in Huainan as the engineering background,the deformation and failure characteristics of the roadway roof were observed in situ and analyzed,and the original support effect was analyzed.Based on the principles of material mechanics,a mechanical model of the composite roof rock layers was established,and the expressions for the deflec-tion of each layer of the composite roof were analyzed.The mechanism of separation instability of the composite roof was re-vealed,then the control mechanism of full-length anchorage and anchor cables on the separation of composite roof was ex-plored,and the joint support technology of full-length anchorage modification combined with long anchor cables was proposed.The results show that the joint support uses the full-length anchorage to increase the elastic modulus of bottom layer of the composite roof,reducing the deflection of bottom layer of the composite roof.Then,it uses the anchor cables to combine the various layers of the composite roof into a whole,forming a composite beam structure,thus the overall deflection of the com-posite roof is reduced.The field monitoring shows that the amount of convergence of the roof and floor plates decreases by 64%,the separation phenomenon is not found in the roof,and the maximum crack depth decreases from 8.1 m to 3.8 m,with the reduction of 53.80%.The stability of the coal roadway is significantly improved.The results can provide reference for controlling the collapse and instability of deep-buried composite roof strata separation.
deep miningcomposite roofcoal roadwayin-situ observationfull-length anchorage
NETL
NSTL
万方数据
