Study on the law of overburden rock movement and fissure development in coal and aluminum co-mining based on particle discrete element method
In this study,the Lyuliang mining area was taken as the research object.A discrete element numerical calculation model of upper coal and lower aluminum coal measure resources co-mining was es-tablished.The stress superposition law of overlying strata under long-wall coal seam and room-and-pillar bauxite seam co-mining was studied.The arching mechanism and superposition transfer characteristics of coal seam roof pressure arch,coal-aluminum interlayer pressure arch and floor pressure arch were re-vealed.The corresponding overburden movement modes under the stability of bauxite pillar,partial pillar instability and overall instability were proposed.The law of strata migration and failure under the super-imposed disturbance of coal and aluminum co-mining was analyzed.The results showed that the bauxite pillars at both ends of the goaf were prone to failure and damage due to the superposition of the com-bined stress arches.Then,it caused the linkage instability of the adjacent pillars,where the bauxite layer has occurred a large scale cut and slip of the overlying strata and a violent phenomenon of mine pressure appearances.The fracture development law of overlying strata under coal and aluminum co-mining was quantitatively characterized by using fractal geometry theory.When the pillar size was small,the fractal box dimension of the bauxite room overburden was significantly larger than that of the undisturbed area of the rock stratum,that the overburden fissures of the mine room have developed through to the coal seam at both ends of the goaf.
万方数据
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