Research On Movement Law Of Overlying Strata In Shallow Buried Large Mining Height

The Shendong mining area is located at the junction of northern Shanxi and eastern Inner Mongolia.Due to the superior geological conditions of the mining area,the Shendong mining area is actively exploring new coal mine technologies with significant innovations and achievement in recent years.While obtaining considerable economic benefits it also destroys the vulnerable ground.The destruction of ecosystems,especially water resources,is particularly serious.It not only affected the safe production of coal,but also caused irreversible damage to the surface environment.Therefore,it is extremely important to study the movement law of overburden rock in large mining height in shallow burial.In this paper,the 12409 working face of the Bulianta Mine in Shendong Minig Area is taken as the research background.The data of the mining area is collected and sorted on the spot.The development law of rock movement and permeable fracture zone are studied.(1)According to the field investigation and expert opinion,the influencing factors(geological factors and mining factors)of overburden rock movement in Bulianta coal mine were screened by fuzzy analytic hierarchy process,and the main influencing factor of overburden rock movement in Bulianta coal mine were determined as mining height and work.Face length,comprehensive hardness of overburden rock and advancing speed of working face.(2)The mechanical parameter of coal and rock were determined through laboratory mechanics experiments and mining area data references.(3)Based on the orthogonal test,9 different FLAC3 D mining models of Bulianta coal Mine were established,the sensitivity analysis of overburden rock was conducted by analysis of variance.The sensitivity of four main control factors to the overburden rock were obtained(height mining,working face length,comprehensive hardness of overburden rock and advancing speed of working face),using stress analysis to study the internal damage of overburden rock,it concluded that the amount of vertical sinking of overburden rock is consistent with the degree of disturbance within the overburden rock.(4)The 3DEC numerical simulation software was used to study the destruction height of overlying rock,that is,the height of the water-conducting fracture zone,and analyze the development law of the water-conducting fracture zone at different mining height.The final development height of the water fissure zone does not increase linearly with the increase of mining height,but increase stepwise.Based on the result of discriminating the key stratum of overlying rock is consistent with the numerical simulation results,the rationality of the key layer location discrimination method of the overburden is verified from the perspective of the numerical simulation,and the development height of the water diversion fracture zone can be further predicted.The research on the movement law of overburden rock in the shallow-buried high-mining stope can not only provide scientific guidance for safe and effective mining in the mining area,but also predict the degree of surface damage,and provide protection for water resource and land in the mining area and green mining.An important reference value,which is important for the sustainable economic development of the mining area.