Study On Rational Distribution Of Surrounding Rock Roadway And Control Of Surrounding Rock In Upward Mining Of Close Coal Seam

The reserves of most mining areas in China are dominated by coal seams in close proximity.With the popularization and application of high-yield and high-efficiency coal technologies in recent years,the mining intensity of underground working faces has increased,and the annual coal output of coal mining enterprises has risen sharply.A considerable number of mines have appeared in service.The coal resources with excellent mining conditions in the years are approaching depletion.Therefore,higher goals and requirements are put forward for the traditional mining methods and technical means of the coal seams in close distance.However,the most mature mining sequence in our country's coal mines is downward mining.Although there are great advantages in solving the relevant technologies such as roadway layout,roof management and other related technologies,coal seams,for example,are unstable coal seams,and coal quality is hard.When difficulties arise in mining and the value of mining is lower than the lower coal,special considerations such as upward mining can be considered,which can help mines or,mining areas achieve high-efficiency and high-yield,and have certain technical advantages.Combining relevant experiences and lessons from up mining in mining areas at home and abroad,the layout of the upper coal seam mining gateway and surrounding rock control technology are the most important factors restricting the safe and high-efficiency mining of up-close coal seam mining.The stability of the surrounding rock in the top coal mining gateway is closely related to the rational layout of the surrounding rock and the supporting measures adopted.This article based on the specific conditions of the 2#coal 6202 coal face and the 4#coal 6403 coal face of the 6th coal mining area of Zhaizhen coal mine in Xinwen Mining Group.Through theoretical calculations,ficld measurements,numerical simulations,and engineering practices,the development height,form,and zoning of the fractured zone of the 4#coal 6403 coal face were investigated.and the stress distribution and damage of the upper 2#coal seam and floor rock were obtained.And the law of surrounding rock deformation,formulate the principle of 2#coal mining roadway layout,and construct the supporting technology system for the differential control of surrounding rock in the roadway with cracks.According to the proposed 2#coal transportation lane and track lane layout plan:? Two lanes wrong 4m layout;?Two lanes wrong 20m layout.But by theoretically verifying the simulation software and considering the actual factors of geological faults,it was finally proposed that the 2#coal 6202 coal face transportation lanes should be laid out with an offset of 20m,and the track lanes should be laid out with a 4m layout,where the excavation is to 140m.To the outside of the gob area parallel to the transition 2 m,that is changed within 2 m wrong arrangement.In addition,three types of supporting systems for 2#coal mining roadway are established accordingly.Include:? High-strength prestressed strong bolt support measures are adopted when the roof is intact;?High-prestressed strong bolts and anchor cables are combined to support the roof when the roof is broken.?When the roof is extremely broken,and the development of surrounding rock fissures is large,high prestressed high-strength bolts and anchors combined with superimposed sheds are used to reinforce and support measures,supplemented by surrounding rock grouting.The feasibility of the entire support program was demonstrated from the theoretical,technical and practical application effects.