The Development Law Of Water Flowing Fractured Zone Caused By 2^-2 Coal In Yushen Mining Area

As a key technical parameter of water-preserved mining,the development height of diversion fissure zone dircetly determines the degree of influence of coal mining on the aquife,and also determines whether it iy neeessary to adopt the water-retaining coal miningprocess to carry out water-retaining mining.The first and third phase planning areas of Yushen Mining Area are located in the core zone of Yushen diggings,which belong to thetransitional area between shallow seam area and deep seam area.The widely distributed submergde aquifer of the Salawusu Formation in the area is an important source of water conservation area.Thesc factors have determined that the area has developed into a key area for waer conservation mining.Therefore,before the large-scale development,the basic problems for realizing the goal of ecological environment proection and green mine construction in the region are obtaining the measured parameters of the water-conducting fractured zone in the mined face,summarizing the development law of the water-conducting fractured zone suitable for the geological conditions of the region,and scientifically predicting the development characteristics of the water-conducting fractured zone in the unmining area.In this paper.Yushuwan Coal Mine,Hanglaiwan Coal Mine,Jinjitan Coal Mine,Caojiatan Coal Mine,Dabaodong Coal Mine,Guojiatan Coal Mine Field and Xiaobaodang No.1 Well in Yushen mining area are taken as the research areas.The research focus is on the development height of the water-conducting fracture zone in No.2-2 coal seam of the first mining coal seam.The development characteristics of water-conducting fractured zones under specific geological conditions in Yushen mining area are studied by drilling survey in goaf,numerical simulation experiment and similar material simulation experiment.The development law of water flowing fractrured zone is revealed,and the prediction formula for scientifically predicting the development height of water-conducting fractured zones in unmninl areas is summarized and put forward.The main conclusions are as followings:(1)Field measurement,numerical simulation,physical simulation and other means were used to comprehensively study the development law of the water flowing fractured zone in the first coal seam mining in the Yushen mining area.And the height of the water-conducting fracture zone is generally between 24 and 28 times mining thickness.(2)The development characteristics of the water flowing fractured zone are analyzed.The development law of the water flowing fractured zone and the caving zone in the single-face coal seam mining are as follows:The central position of the working face is the largest,and the slot position along both sides is slightly smaller.The top boundary contour extends to the inside of the working face,and there is little change along the inclined height of the working face.The spatial form is "pan-shaped" with the maximum in the middle and slightly lower on both sides along the inclination of the working face.(3)The multivariate linear prediction equation is established by taking the maximum height of the water flowing fractured zone as the primary factor and seven factors as independent variables,which are mining depth,mining height,rock-soil ratio,sand-mud ratio,sand layer coefficient,average thickness of sandstone and comprehensive hardness of overburden.