Study On Time Process Of Ground Movement In Steep Coal Seam Mining

Ground subsidence caused by underground coal mining is a space-time process. Coal seam pitch is one of the most important factor which determine movement and failure forms of overlying rock and the level of ground movement and deformation. In the previous research, because mining subsidence's inoculation and developing process is so complex that can't touch, people give more attention on final result of rock damage; the overlying rock of steep coal seam mining have different homogeneousness in horizontal orientation. It's complexity make the research of this kind of problem's time process is very inadequate. All of those are disadvantages of mining subsidence's forecast and prevention. Both traditional continuous medium mechanics and discontinuous medium mechanics have extreme pertinency, one of it's shortcomings is that when we simplify the rock model, we look the rock on the working face as a static beam, and ignore impelling change of the working face and property and load change as the overlying rock is destabilizing, so the cross-section equation we produced only is a final approximate subsidence expression, not a dynamic subsidence process of the rock. From these views, through phenomenon experiment theory thought mode, be based on ideal loose body and random medium theory, this thesis make study on rule of steep coal seam mining step by step. This thesis put forward a new probability density function of overlying rock and ground subsidence which have general statistic meaning. Be based on which, the thesis establishes a new ground subsidence and deformation prediction theory of steep coal seam mining, and put forward a new method of ground subsidence and deformation prediction for mine exploitation.