Study On Surface Subsidence Prediction Method Based On Movement Characteristics Of Primary Key Stratum

This dissertation studies the influence of the dynamic movement process of mining-induced primary key stratum on surface subsidence through mechanical theory analysis,similar simulation tests,numerical simulation calculation,and measured data verification.This dissertation establishes the prediction method of surface subsidence under different movement characteristics of the primary key stratum based on the principle of probability integral.This dissertation reveals the internal movement mechanics mechanism of the mining-induced overburden.It improves the prediction accuracy of surface subsidence.The main research results are as follows:This dissertation reveals the influence mechanism of the primary key stratum’s curved or fractured movement structure on the surface’s subsidence morphology and mining-induced degree based on the simulation test.When the primary key stratum curves subsidence,the connecting line of each key stratum and surface subsidence inflection point is concave curve morphology.The maximum subsidence value of the primary key stratum and surface increases linearly with mining.When the primary key stratum fractures subsidence,the connecting line of each key stratum and surface subsidence inflection point is an exponential morphology.The maximum subsidence value of the primary key stratum and surface presented a power function-increasing trend with mining.Based on the movement structure and stress distribution characteristics of the primary key stratum,considering the supporting effect of the fractured rock,this dissertation established the mechanical model of the primary key stratum with four-side elastic support and the middle suspension(contact waste rock).Based on the transfer shearing of the fractured rock,this dissertation established the mechanical model of the primary key stratum with three-side elastic support,one-side bearing shear force,and the middle suspension(contact waste rock).Based on the mechanical model of the primary key stratum with four-side elastic support,this dissertation established the prediction method of curved subsidence of the primary key stratum of the middle suspension(contact waste rock).This dissertation studied the curved subsidence morphological characteristics of the primary key stratum of the middle suspension(contact waste rock)and the variation law of the maximum curved subsidence value of the primary key stratum of the middle suspension(contact waste rock)with the calculation parameters.Based on the mechanical model of the primary key stratum with four-side elastic support and the mechanical model of the primary key stratum with three-side elastic support,one-side bearing shear force,this dissertation studied the structural characteristics of the first and periodic fracture of the primary key stratum of the suspension and contact waste rock.Based on the fracture structure characteristics of the primary key stratum,this dissertation established the prediction method of the primary key stratum fractured subsidence of the middle suspension(contact waste rock)and analyzed the variation law of morphological characteristics of the primary key stratum fractured subsidence with calculation parameters.Combined with the spatial morphological characteristics of curved subsidence of the primary key stratum,this dissertation established the surface subsidence prediction method of the curved primary key stratum of the middle suspension(contact waste rock).Combined with the spatial morphological characteristics of fractured subsidence of the primary key stratum,this dissertation established the surface subsidence prediction method of the fractured primary key stratum of the middle suspension(contact waste rock).This dissertation established the discrimination method of the primary key stratum with the middle suspension or contact waste rock structure and the calculation steps of the surface subsidence prediction method.This dissertation verified the reliability of the surface subsidence prediction method based on the movement characteristics of the primary key stratum by the surface observation data of the 303 working face in the third-panel area of the Tingnan Coal Mine,the 1312(1)working face in the south-one mining area of Gubei Coal Mine and 31401 first working face in the fourth-panel area of the Bulianta Coal Mine.This dissertation’s research content benefits the mining subsidence discipline system.It has important theoretical significance and application value for the prevention and control of mining damage and environmental protection of mining areas.There are 129 figures,20 tables and 199 references in this doctoral dissertation.