Simulation Of Overburden Failure And Water-conducting Fracture Zone Development Height In Jurassic Coal Mining Area Of Northern Shaanxi

In the process of coal mining,there are problems of water resource loss and vegetation ecological environment degradation.To ensure the protection of groundwater in the coal mining process is the basis to realize the efficient development and utilization of water resources and coal resources.In this paper,Daize Coal Mine in Northern Shaanxi was taken as the main research area.Through numerical simulation and measured data,the factors influencing the development height of the water-conducting fractured zone were analyzed,and the development height of the waterconducting fractured zone was simulated under a variety of mining schemes.The weight of the main controlling factors of the water-conducting fractured zone was obtained,and the comprehensive evaluation of the mining scheme was completed.It provides a scientific basis for the mining scheme to reduce the overburden rock damage and restrain the development of waterconducting fractured zone,and protects the water resources and ecological environment in the mining area while exploiting as much coal resources as possible.The main conclusions are as follows:(1)The development height of the water-conducting fracture zone is linearly related to the mining thickness.The greater the mining thickness,the higher the development height of the water-conducting fracture zone.Generally,the height of the water-conducting fracture zone is about 10-20 times the thickness of the coal seam.(2)The development height of the water-conducting fissure zone is related to the lithology of the coal roof.The height of the water-conducting fissure zone of the hard roof>medium-hard roof>soft roof.(3)After the coal seam is mined,the overburden stress in the goaf is divided into tensile stress area,compressive stress area and surface tensile stress area from bottom to top;the stress on the coal wall at both ends of the goaf increases sharply,resulting in stress concentration.Far away from the coal wall,the stress gradually decreases and tends to stabilize,and the overburden stress presents a stress arch structure.(4)The influencing factors of the development height of the water-conducting fissure zone are as follows: mining thickness> roof lithology> mining method> slope length of working face>mining depth.The mining thickness of the coal seam is the most important factor affecting the development height of the water-conducting fractured zone.