近一百多年来,岩层移动研究方面先后出现了“拱”、“圆顶”、“天然边坡”、“法线”、“变形带”和“棱柱体滑动”等理论。它们多因有较大的局限性而被放弃,其中只有棱柱体理论被保留下来,在实际中有所应用。 (一) 棱柱体理论棱柱体理论认为:空区上部地面陷落是因在重力的分力(下滑力)作用下,空区上部冒落拱向上发展后周围斜棱柱体沿斜面下滑的结果。随着采深的增加,顶(底)盘不断出现新滑动棱柱体,其横剖面下滑线与水平线构成的陷落角也逐 In the recent one hundred years, theories such as “arch”, “dome”, “natural slope”, “normal”, “deformation zone” and “prism slide” have appeared in the study of rock movement. They are mostly abandoned because of their larger limitations, of which only the prism theory has been preserved and has been applied in practice. (I) Prism theory Prism theory holds that the fall of the upper ground in the empty area is the result of the sloping sliding around the oblique prism along the slope after the upper arch of the empty area develops due to the component of gravity (sliding force). With the increase of mining depth, a new sliding prism continuously appears in the top (bottom) plate, and the falling angle formed by the sliding line and the horizontal line in the cross section is also decreased