Study On Surrounding Rock Control Technology Of Gob-side Entry Retaining InLarge Mining Height Coal Face Of Liujiazhuang Colliery

Based on the engineering background of gob-side entry retaining in the thin seamcoal full mechanized face5211of Liujiazhuang colliery, and by comprehensive usingof theoretical analysis,numerical simulation, engineering analogy and the method ofindustrial test, this thesis analyzed, the characteristics of gob-side entry retainingandcontrol technology of surrounding rock of gob-side entry retaining. Research resultsare summarized as follows：Analyzing lawof lateral roof broken, drawing conclusionsas follows:key blockplays an important role in gob-side entry retainingstability of overlying roofstructure,packing body,as a support point,resisting the movement of mainroof,determines the stability of surrounding rock of entry retaining.More detailed analysis was conducted on stress evolution law and deformationregulation of surrounding rock during roadway drivage, mining influence andstationary phase. Then the characteristics of gob-side entry retaining with limestoneroof of thin coal seam were analyzed, getting the conclusions of roadway side supportshould have high strength and high plasticity, and support strength of roadway sideshould match mechanical properties of roof and floor.More research are conducted bynumerical simulation on influencing factors of surrounding rock stability in gob-sideentry retaining of large mining height work face,drawing conclusions as follows:roofcarving height is higher,stress concentration factor is larger,given deformation of themain roof is larger,plastic area is bigger.According to large mining height work face gateway defomation characteristics,then this paper put forward control method of surrounding rock pointedly: boltingshould be as the basic support and high-water rapid hardening materials should be theroadway side support for gob-side entry retaining,besides,roof above packing bodyshould be reinforced with cable supporting and single hydraulic prop as temporarysupport in roadway.Research results above were applied successfully in Liujiazhuang colliery, andthe social, technical and economic benefit was terrific.