Research on the Setting and Support of Small Coal Pillars in the Driving Roadway Along Goaf of Fully Mechanized Caving Face in Extra Thick Coal Seams
In order to study the reasonable width of small coal pillars setting in the driving roadway along goaf of the fully mechanized top coal caving face in extra thick coal seams,the return air roadway of the 8117 working face of Tashan Coal Mine is taken as the research object,and a combination research method of theoretical calculation,numerical simulation,and on-site measurement is used for research.The research shows that after the adjacent working face goaf is stabilized,the range of the lateral support stress reduction zone in the coal body is 0 to 13.7 m,and the width of the coal pillar below 8 m can ensure that the return air roadway of the 8117 working face is in the stress reduction zone,which is conducive to the stability of the surrounding rock of the roadway;When the width of the coal pillar is greater than 8 m,the elastic zone inside the coal pillar increases with the increase of the coal pillar width,and the vertical stress in the middle part of the coal pillar begins to exceed the original rock stress;The final decision is to use an 8 m small coal pillar.The on-site observation indicates that when an 8 m coal pillar is set,the displacement amount of the two sides of the roadway and the subsidence amount of the roof and floor of the 8117 return air roadway are relatively small during the excavation and mining stages.The coal pillar can effectively support the roof and control the deformation of the surrounding rock.
extra thickfully mechanized top coal cavingalong goafcoal pillar
万方数据
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