Research Evolution Law For Fracture Of Mining Overburden In Dafosi Coal Mine And It’s Application

The study on the behavior of overburden fractures evolution after mining is the key to thelayout of high-located gas drainage roadways. Putting the high-located gas drainage roadwaysin the gas delivery channels is good for the gas drainage. Using the overburden structure in40108face of Dafosi Mine as the model, the rational use of high-located gas drainageroadways was analyzed based on the previous researches. In this study, the similar simulation,numerical simulation and field test are used.Using the theoretical analysis, the principle of Mining Fissure Elliptic Paraboloid Zoneproviding space for gas preserving and delivery was represented. Based on the experiments,the behavior of fractures’emergence and development and the generation of Mining FissureElliptic Paraboloid Zone after mining were revealed. By integrating the similar simulation,numerical simulation, theoretical analysis and field test, the height of caving zone wasobtained. Based on the theory of high-located gas drainage roadways and the drainage data ofthe roadways in40108face of Dafosi Mine, the location of drainage roadways was settled inthe fractured zone by analyzing the relation between the roadways’ height and drainage mixedflow, subpressure, gas concentration, gas net measure CO concentration and CO net measure.In that analysis, the influence of the height on the spontaneous combustion in goaf was alsoconsidered. This location could improve the efficiency and concentration of drainage andbring about the safety requirement of gas prevention.