A SURFACE SUBSIDENCE MODEL OF COAL SEAM MINING IN MOUNTAIN AREA BASED ON PLATE BENDING DEFORMATION¹⁾

According to the theory of the “three zones” of failure and movement of the overlying strata in the longwall mining face, the subsidence deformation of the surface is controlled by the bending subsidence zone, and the maximum subsidence of the surface is far less than the thickness of the bending zone strata, therefore, the deformation of the bending zone strata conforms to the small deflection bending of a plate. On this basis, according to the characteristics of the mountain topography and the landform and the relationship between the slope direction and the coal seam tendency, the surface mountainous body is simplified into four cases: that with a forward slope, that with a reverse slope, the trench and the mountain ridge. The surface subsidence basin models in the four cases are established by a semi-inverse method of the thin plate theory. Despite some simplified assumptions in the model, the main factors affecting the mining subsidence are considered, such as the coal seam dip, the burial depth, the physical and mechanical properties of the strata, and the geomorphological shape.