Study On The Reasonable Size Of Coal Pillar For Coal Mining In Xinji No.2 Coal Mine

Xinji No.2 coal mine is mining 2101 and 2202 mining areas.The mining coal seams are 1 upper coal seam and 1 coal seam.There is only one layer of mudstone intercalated gangue between 1 upper coal seam and 1 coal seam.The thickness is 0-2.2m and the average is 1.1 m,which can be defined as extremely close coal seam.During the mining of extremely close coal seam,there may be a through fracture between the goaf of No.1 eoal face and No.1 upper coal working face under mining,resulting in fresh air flowing into the goaf,causing spontaneous combustion of residual coal in goaf and increasing the difficulty of fire prevention and extinguishing.Therefore,it is of great significance to study the reasonable size of coal pillar in coal mining to prevent spontaneous combustion of residual coal.First of all,in the case of the same goaf,the coal leakage flow field in the same goaf is simulated by the calculation of the same goaf flow field.No.1 Coal and No.1 upper coal in no.2201 mining area of Xinji No.2 mine are mined at the same time.Therefore,taking 2201 mining area as the research object,the energy level test and tracer gas experiment are used to study the goaf flow field and air leakage channel.Then,the elastic core theory and empirical calculation method are used to calculate the coal pillar width under the existing mining conditions.The width of coal pillar is the main factor affecting the stability of coal pillar and the maintenance of roadway.The width of coal pillar determines the horizontal distance between roadway and mining space,and affects the influence degree of abutment pressure caused by mining on roadway and the load of coal pillar.Theoretical calculation is carried out to ensure that the coal pillar has a strong theoretical support.Finally,in order to study the parameters of the small coal pillar in the mining of No.1 coal seam from the macroscopic point of view,in view of the advantages of the similar test,such as strong intuition,good flexibility,high efficiency and good repeatability,the physical simulation of the excavation of coal group 1 is carried out by using the physical test of similar materials.The deformation and failure of overburden rock in the mining process of coal face are studied by using the similar simulation experiment method.Using cm-2b-64 data collector,the strain data can be collected automatically.The direct data collected is micro strain(10-6),which can be multiplied by elastic modulus to obtain the stress change.The reasonable size of coal pillar in 1 Coal Group Mining is estimated by experiment.Figure[31]table[6]reference[76]...