Research On Overburden Deformation Law Of Filling And Mining Based On Improved Foundation Beam Model

Filling mining technology is a rare green mining technology in the coal production process.Through years of application and research,this technology has made great progress in theory and practice,effectively solving the problem of "three down" coal in some mining areas.In filling coal,the filling material enters the goaf to support the overburden,which is equivalent to alleviating the disturbance caused by coal mining.The strong support of the filling material to the rock strata causes the law of the movement of the overburden to be very different from the law of the traditional mining method.Based on the theory of foundation beam and the theory of limit equilibrium zone,this paper systematically studies the law of overburden deformation during filling and unfilling mining by means of theoretical analysis and numerical calculation.The main work is as follows:(1)Considering the plasticity,horizontal deformation of the coal body in front of the working face and the influence of the interface slip between the coal seam and the basic top,the foundation is subdivided into plastic zone,transition zone and elastic zone,and a new elastoplasticity is established.Based on the mechanical model of the foundation beam,the basic reaction force based on these three parts is derived,and the deflection curve equation is numerically solved.The numerical simulation is carried out with FLAC3D.The new elastoplastic foundation beam mechanical model is found through comparison.The results are more suitable for our needs.(2)A large number of numerical calculations are carried out on the mechanical model of the elastoplastic foundation beam of the stope roof,which is used to reveal the movement and deformation law of overlying strata under the influence of buried depth,length of goaf and foundation height.(3)Based on the mechanical model of the elastoplastic foundation beam of the stope,the mechanical properties of the elastoplastic foundation beam in the filling mining are established,and the expression of the ground reaction force and the deflection of the roof are determined.Solution,through a large number of numerical calculations,the effects of five factors,such as the foundation foundation coefficient,buried depth,basic top elastic modulus and thickness,and the amount of sinking when the roof is in contact with the filling body,are analyzed.