Similar Simulation Study on Key Layer Determination and Migration Law of Overburden Rock in Extra-thick Coal Seam
In order to find out the overburden migration law of the W1123 working face of Kuangou coal mine under solid coal and goaf area,builds a physical similarity simulation experimental model of the direction of the comprehensive surface,uses the total station and dial meter to regularly and comprehensively monitor the overburden migration and subsidence value of the working face during the recovery process of the model,discusses the influence of key layer and extra-thick coal seam on overburden collapse,and analyzes the overburden migration law.The results show that the coarse-grained sandstone with a layer thickness of 15.9 m is the main key layer;when the W1145 working face is mined to 104 m,the old roof of the working face overburden collapses,forming an arch-shaped stable structure composed of the main key layer,and when the mining reaches 192 m,the remining of extra-thick coal seam produces strong ore pressure and converges to the main key layer,and the overburden structure controlled by it is unstable,resulting in a large area of collapse,the ore pressure appears strong,and the maximum sinking value reaches 1.4 m at the end of mining;when W1123 working face is mined to 396 m,a crack appears in the rock layer 10 m from the front of the work and suddenly collapses,and the two working faces penetrate,the maximum sinking value is 2.6 m,and at the end of mining,the maximum sinking value is 1.38 m.Provide a scientific basis for the stability study of rock formations in the goaf area.
overburden migration lawkey layerphysically similar simulationsolid coalsink value
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