Study On Layout Of Mining Roadway And Strata Behavior In Close Distance Coal Seam

Coal occupies a major position in China's energy structure,in many mining areas of China there are close coal seam mining situation.It is an important problem that affects the safety and benefit of coal mine in crushing,deformation and support of roadway in short distance coal seam.The original stress balance state after the coal mining is broken,the concentrated stress caused by the deformation of the floor will cause damage,the distribution of the stress field of the floor and the depth of the damage is an important factor to determine the location of the roadway.When the coal seam is closer,the upper and lower coal seams have a greater impact on each other.When the coal seam has a large inclination angle,the excavation roadway is difficult to support,the maintenance cost is greatly increased,and the control of the surrounding rock is easy to cause the safety accident.The stability of the mining roadway is related to the safety,high yield and high efficiency of the coal mine.Therefore,when the mining roadway is arranged,the mining roadway is in the low stress area,and the deformation of the roadway is minimized to ensure that the mining roadway can meet the requirements of ventilation,pedestrian and transportation during the excavation and mining.Based on the theory of slip line field,the influence range of the plastic zone of the remaining coal pillar and the depth of the bottom plate failure are calculated in the case of B6 coal mining in the upper coal seam.According to the calculation results,it is concluded that the layout of B4 coal roadway is selected.The FLAC3D numerical simulation software is used to analyze the mechanical characteristics of the roadway surrounding rock and the displacement of the roadway in the roadway with different internal fault distance and open cut position.Combined with the site geological conditions,4671B4 face is in the 4671B6 working face under the goaf,B6 and B4 coal seam is stable,the average distance between the two layers of coal is 22m,the work of the roadway layout and the geometric size of the work surface requirements are higher.According to the final verification of the actual data,the reasonable location of the roadway layout is determined,which avoids the deformation and damage of the roadway surrounding rock,improves the production capacity,reduces the production cost and creates favorable conditions for the construction of high production and high efficiency mine.