Study On Caving Method Ascending Mining Of Closed Distance Thin And Thick Seams

Application of ascending mining in coal mining in China, not only play an important role in improving economic efficiency, and also provides a great technical support on safety production in the specific geological and mining condition, scientific utilization of ascending mining for coal mine safety production service has become an important issue. Therefore, study on the law of overlying strata movement in ascending mining, has the extremely important theory value and practical significance to explore the mechanism of ascending mining.For a mine to maintain the stable production ascending mining technology is used, through the field core to obtain the mechanical parameters of rock, and according to the actual mining situation to create three different mining model, using the theoretical calculation, similar material simulation and numerical simulation to study the ascending mining. Fist, the "three zones" method, ratio method, rock balance method was used to study the theory feasibility of ascending mining for the three model, found that three kinds of discriminant method on specific geological and mining condition exists inconsistency; Then the similar material simulation and numerical simulation method were used to study appear law of mining pressure for mining face, stress distribution, displacement deformation law, surrounding rock failure characteristics and distribution of plastic zone, macroeconomic research of the influence to overlying strata of mining sequence and roadway layout of ascending mining was also made. The experiment found that in the three model, the whole6coal group continuity was not badly damaged, bench convergence and stress concentration anomaly phenomenon which result in significant impact on ascending mining were not happened too. In order to further study the feasibility of ascending mining,"water seepage law" was used to measure the height of "two belts" after the seam was mined, the results revealed that the caving zone height of mining height is14-16m,the height of fiactured zone is50～54m,it in good agreement with theoretical results, similar material simulation and numerical simulation results of the corresponding model. Based on the above analysis, the ascending mining of closed distance seams is feasible and also reveals some empirical formula under the special geological conditions and mining conditions to be perfected.