Study On The Influence Of Key Stratum Breakage By Hilly And Gully Terrain In The Shallow Coal Seams Face

Shendong Shangyuquan coal mine is a shallow buried mine, the surface full of hilly and gully terrain, and I031001 mining face encountered many problems such as fully mechanized supports crushing accident and sidestepped subsidence, Comprehensive analysis shows that the current study on the breakage law of key stratum under the Non-uniform load of the valley doesn’t exist yet. By adopting the method such as the theoretical analysis, numerical simulation and industrial validation, this paper researches the breakage law of key stratum under the Non-uniform load of the valley, which is different from O type theory, and the industrial validation was successful. The main conclusions are shown as follows:1)In order to quantify the impact of gullies occurrence of critical layers, this paper derived the formula of additional stress when valley existed, the valley will lead to different strata stress distribution. this paper derives the formula of the additional stress of critical layers at the valleys platform and slopes2)Analysis with the method of Marcus reduction algorithm on key strata valley breakage. According to Marcus reduction algorithm, the hanging plate layer after mining key can be simplified to strip beams model, by loading overburden hydrostatic pressure and additional stress of surface valley, this paper derived a formula for calculating the respective bar section force beam. With structural mechanics solver the paper made the formula results graphical. Based on these the paper speculated the key stratum rupture rule under the effect of valley.3)Numerical simulation analysis on the key stratum breakage law under valley occurrence impact. Using FLAC3 D software shell member by loading overburden hydrostatic pressure and the additional stress imposed by different valleys occurrence, the paper analyzed the influence of slope angle and valley plagioclase, which lead to a breakage law not same with critical O-rings.4)Engineering Practice. The paper compares the difference between the actual breakage law and theoretical results previously discussed, and Shangyuquan I031001 mining validated the speculation in practice...