Research On Roadway Layout And Support In Close Coal Seam Under Upper Gob In Deep Mine

With mining depth increasing and mining range enlarging,the difficulty of roadway support is increasing.When mining in closed coal seam,or coal pillar left after extraction in upper coal seam,the distribution of stress and roadway support in lower seam could be affected.When roadway close to upper gob,bolt-mesh support can not be applied as only method.Because the rock mass under upper gob is broke in certain range,the roof of lower-seam roadway is difficult to form a self-stabilization structure.When roadway was in geological structure region or in bad lithology,the roof would be more broken and the support would be more difficult.Aiming at roadway supporting in coal seam closed upper gob in the Dongtan coal mine, research the influencing factors which affect roadway support,furthermore,to confirm the reasonable roadway layout and optimize the support way.Practical observation and numerical simulation method were applied to research the affect of different quality and thickness on support of roadway in lower coal seam,provided the reference for choosing support way; Mechanical analysis and numerical simulation were done forâ… beam set supporting to research the holding power ofâ… beam set;Research result in Dongtan coal mine 4307 coal face was applied to prove the rationality of roadway layout and support way.The rule of rock pressure in the coal seam close to upper gob was observed.The research result could provide tequnical reference for other similar coal mine on support problem of closed lower coal seam.