Study On Strata And Surface Deformation Law Of Minng Steeply Inclined Coal Seam In Zhao Fu Coal Mine

As the strength and range of coal mining are expanding increasingly with mining year by year,the decrease of high quality coal makes the coal mining translate into complex coal seam gradually.As one of the common complex coal seams,steep-inclined coal seam is distributed widely in China.There have been many coal mines exploiting the steep-inclined coal seam,but the relative laws of strata movement and studies on surface subsidence prediction are not perfect,and we need to enhance the relative studies in this areas.Based on Zhao Fu coal mine,this paper studies the laws of overlying strata movement and ground deformation of steep-inclined coal seam by using the methods of mechanical analysis,numerical simulation and laboratory test.The main modes of strata movement of mining steep-inclined coal seam are caving,bending and slipping.Because steep-inclined coal seam has a relatively large dip angle,there is a big force along the bedding surface.In this way,roof strata will have slipping deformation mainly which is much more important than bending.Based on the analysis of the coal seam roof,this paper establishes the mechanical model of the roof,calculates the deflection and slippage of the roof,and analyzes the failure limit of the roof strata.This paper establishes the numerical model of horizontally mining steep-inclinced coal seam in Zhao Fu coal mine,and analyzes the possible situation that will happen in the coal seam mining.The numerical models of mining steep-inclined coal seam in different conditions are established.And in this way,it studies that the changes of dip angle and thickness of coal seam as well as the vertical height of goaf have the influence on the distributions of vertical stress and horizontal stress of overlying strata,destruction region states of overlying strata,movement patterns of roof rock and the surface.According to the results of steep-inclined coal seam's overlying strata movement and surface deformation,it translates steep-inclined coal seam into horizontal coal seam with Slip Space Transformation Method,and predicts the mining subsidence by using Probability Integral Method.And it analyzes the damage of surface's movement and deformation based on the prediction of surface's movement and deformation.