Physical modeling on deformation characteristics of overlying rock mass above mined-out area in gently inclined coal seam

Using Madaling landslide in Guizhou Province as a case,based on physical modeling,this paper studied the deformation process and mechanism of overlying rock mass above a mined-out area in gentle inclined coal seam. As a result,the mining landslide deformation mechanism could be described as follow:firstly,the coal mining leads to the stress redistribution of overlying rock mass and tensile stress concentrated area along mined-out boundary. Secondly, the overlying rock mass subsides and generates bending deformation. At the same time,the shoulder and toe region of the slope moves outward and generates horizontal displacement. Thirdly,cracks generate at the back edge of the mined- out area. After mining coal pillars,the cracks further extend and gradually form potential sliding surface combining mined-out area.