Overlying Rock Failure Law And Observation Of “Two Zones” In 3-1 Coal Seam Of Mataiyu Coal Mine

Dongsheng coal field has the advantages of large coal thickness,small dip angle,simple geological structure,etc.,forming a high-strength mining mode with large mining height,fast pushing speed and large output.The coal field is located on the edge of the Mu Us Desert,where surface water and groundwater resources are scarce.High-strength underground coal resources mining poses a serious hazard to the local ecological environment,and also poses a great threat to the safe mining of coal seams under near water bodies.The thesis takes the Mataihao Coal Mine of Dongsheng Coalfield as the research background object,and adopts a combination of on-site investigation,theoretical analysis,numerical simulation,similar simulation and on-site measurement.Conducted in-depth systematic research and achieved the following results:1.Based on the mine geological data and rock physical and mechanical experimental results,based on the "key layer" theory,the height of the overlying strata of Mataihao Mine’s stope was predicted,and the developmental height of the overlying strata of the 3101 working face was approximately 77.7m.The developmental height of the overlying strata of 3102 working face is about 112.91 m.2.Using the method of combining numerical simulation,similar simulation experiment and on-site observation,the movement law of overburden rock in 3-1 coal seam stope was studied,and the steps of initial and periodic pressure in 3-1 coal seam working face were determined.The key stratum of the overlying strata of the working face controls the distribution and development of the height of the two overlying strata.The collapse zone develops near the sub-critical layer and the water-conducting fissure zone develops near the main critical layer.3.Combining the geological exploration of the test face with reference to the theoretical analysis results and on-site measured data of the heights of the two belts of3101 and 3102,it is expected that the height of the fissure zone of the Mataihao 3-1coal seam face will be in the range of 77 m ～ 97 m.