Study On Gas Distribution Law In Adjacent Layer Of Exploitation Working Face Goaf

In North west China,coal are of the characteristics of shallow burial depth, epipedon thin, large thickness and Multi-Layers.There will be different effect on the gas control because different gas resources.Mastering the gas distribution laws in goaf is the premise of extracting and control gas.Determining and analyzing the deformation failure laws of Strata Especially the the range of three-belts is the most important thing.Different gas distribution caused by different mining sequence.These studies will provide theoretical basis for controlling gas in extraction space. So these studies have import academic significance, technology and economic values. So relyed on the great project of Inner Mongolia technology department "Study on the Gas Drainage and Utilization of high gas mine in Wuda Coal Mining District" and production practice of Wuhushan mine, the thesis give a study on the gas distributiong and controlling technique under different conditions and get conclusions in the following aspects:(1)Basic mechanical parameters of coal,roof and floor such as density, elastic Modulus, poisson ratio,uniaxial compressive strength are got by laboratory test,which laid a foundation for the following works.(2) Mathematical model of gas flowing in goaf has been established by theoretical analysis and summarizing previous research.(3) The space-time evolution regularities of roof overburden falling in coal seams mining have been studied by theoretical analysis and numerical simulation.Stress Simulation showing that:the height of the watering fissures is22.9m and the height of caving zone is about10.9m after the mining of the over layer mining.After the under layer mining the height is about14.8m and49.4m.Crack field Simulation showing that:the development and distributing of the fracture fields are more at the edge and less at the middle.The porosity curve take a "saddle pattern" with the trend.(4) Gas distributiong laws in goaf, along the trend and tendency of face, along the transport tunnel and return airway have been studied by theoretical analysis and numerical simulation.Tailgate on effect law of goaf gas flow under different sources of gas emission have been studied by theoretical analysis and numerical simulation. Practice is further evidence of the correctness of the findings(5) Design and Optimization of high position bore-hole parameters along roof strike.3-4group drilling fields with different amount and different depth drillings will be designed.To investigated the relationship between the amount of drainage, advance distance, advance speed and the time of drainage.The results showing:1) Extracting results is the best of the drilling at Lower Slice and the poorest of the drilling at middle when the under layer is the first mining.The analytical results about diring layer and gas distributiong areconsistent with the Theoretical Analysis when the over layer is the first mining.2) In order to master the temporal and spatialevolutionary relationship with drilling and face mining.The final purpose is to determine the rationalizational spin-hole arrangement parameters.By above research, masterring the gas resources and gas distributiong laws in order to determine the temporal and spatialevolutionary relationship with drilling and face mining and the rationalizational spin-hole arrangement parameters.According to these studies, confirmed what technology functions are required and provide the technical support for gas controlling in Wu Hushan mine.