Study On The Fracture Structure Characteristics Andthe Guide Water Fissure Zone Of Caiyuan Coal Mine In Tengnan Coalfield

Water inrush in coal mining face is a major threat to mine mining.How to effectively predict and control water inrush is not only involved in the economic cost of coal mining,but also on the personal safety of underground workers.A large number of cases of water inrush in coal mine show that fracture structure is an important control factor for water inrush in coal mine,so it is an important breakthrough point to find out the geometric characteristics of fracture structure,movement process and the sealing property of main fault,which is an important point to solve the problem of water inrush in the working face of Chua yuan coal mine.Based on underground geological investigation and comprehensive utilization of seismic and drilling data,we have identified the structural styles and kinematic characteristics of the main faults in Cai Yuan coal mine.According to the fault fractal method,the fractal dimension characteristics of the fault in the mine range are evaluated and studied.The sealing characteristics of the main water cut faults are studied by the method of fault sealing evaluation,and the height of the water conducting fissure zone in the working face and the shadow on the working face mining are discussed with the theoretical calculation,numerical simulation and the actual test verification.Ring.Through comprehensive analysis of the above results,the study area is classified and classified for water inrush prediction.The following results are achieved:(1)There are various types of fracture structures in the Cai yuan coal mine,and the strike slip structural styles include the wild goose,flower,broom and sawtooth,and the extensional structural styles include the parallel,comb and staircase,and the extrusion structure includes the shape of the human,the X shape and the imbricate.(2)The Cai yuan coal mine has experienced at least two periods of extrusion and two periods of extensional tectonic movement since the coal formation period:the first stage of extrusion occurred in the early Middle Jurassic before the Mengyin formation,the second period was the late Cretaceous to the Cenozoic generation after the Mengyin formation,the first stage was born in the early Cretaceous,and the second period was mainly extended.The Quaternary period?(3)The near SN trending fracture developed in the late Cretaceous period,cutting to the bottom of the quaternary system,plays a key role in controlling the water inrush in the mining area,and the boundary main fault(Zhu Meiji fault)is an important(guided)water fault.(4)The lateral and vertical sealing ability of F78 fault in main fault is good,which results in little possibility of water bursting at work face.(5)From the feature of fault fractal dimension,area ?(<1.3):in the southwestern part of the mining area,the region in the south of the F78 fault is a safer region;the second region(1.3?1.5):in the north of the mining area,the region in the north of the F78 fault,as the transitional zone of the ? and the ? region,is moderate in the danger of water inrush;zone ?(>1.5):distributed at the edge of the mining area.The boundary fault and the North West South East to the F78 fault in the middle of the mining area,the region is subjected to multiple periods of extrusion and destruction.In this area,the fracture development density is high,the rock strata near the fault zone are relatively broken and the water conductivity is stronger,which is the important water inrush prevention area.(6)From the practice of mine and adjacent ore mining,the numerical simulation of the height of 24.7m and the field measured value 21.5m,with good consistency,that is,it will not destroy the main aquifers in the mining area under normal mining conditions.Therefore,for mining 3 coal seam,the height of the maximum water flowing fractured zone above the roof is 24.7 meters,which is safe.