Simulation Research On The Surface Moving Rule Due To Mining In Steep And Multiple Coal Seams

Surface subsidence caused by underground mining is a complexprocess of time and space, and for the mining in steeple slope and multi-seam the obliquity of coal measures is one of critical factors to determine the moving and destruction form of overlying rock seam, and the degree of surface movement and deformation. In the past study, researchers usually concentrated their attention on the final result of rock breakage, so that the study to this issue is not sufficiency in deed, because the overlying seams present a non-homogeneity in horizontal in the condition of steep and multi-seam, which results in the subsidence processes more complex and in defect of a magnitude of measurement data, and thus the proper estimation and prevention and cure for the mining in steep and multi-coal seams. Both of conventional continuous medium mechanics and noncontiguous medium mechanics, having strong pertinence, can abstract and simplify the rock model in research procedure, in which the rock body lying over the coal face can be considered as a static beam or board to leave out the push changes and the changes of property and load during the stability of overlying rock deformation has lost. Hence the derived profile equation is only the approximate expression of final subsidence of surface after the mining finished, and it is difficult to obtain the dynamic subsidence process of rock body.Based on the conception as above, by means of the simulations in resemble material experimentation and numerical value, the thesis presents that with ideal loose-masses model to study the rule of surface movement and the breakage rule of interior overlying rock in steep and multi-seams mining, and an ideal loose-masses model of steep and multi-seams mining is established based on random medium theory.Meanwhile, some new functions of probability density for worked overburden seam and surface subsidence are put forward here, that with general statistics significance, by which the forecasting system for surface movement and deformation in the condition of steeply slope and multi-seams mining is established to provide a new method for the forecasting the surface movement and deformation in coal mining.