Roadside Supporting With Concrete Brick Wall In Gob-side Entry Retaining

In the traditional coal mining, roadway maintenance often requires leaving in partof the coal pillar, which resulted in significant loss of coal resources. In order to rationalexploit the coal resources, enhance the coal resources recovery, most coal mines in ourcountry have to maintain roadway by gob-side entry retaining. Its advantages havereducing the amount of roadway excavation, reduced roadway excavation rate, improveroadway maintenance, significant of economic and technical benefits and so on. Thesuccessful of gob-side entry retaining lie in the choice of roadside support and entry-insupport. So it’s very important to research of the reasonable support in gob-side entryretaining.Based on the geological condition of fully-mechanized face in nearly horizontaland middle thick coal seam of Guangneng coal-electricity group, the supporting schemeof gob-side entry retaining in3112face of Longtan mine was compared, the rational andeffective supporting scheme of gob-side entry retaining was obtained by usingcombined research of the theoretical analysis, the numerical analysis and the fieldmeasurement. There main search achievements are as follows:(1) Studied on the moving rule of surrounding rock and established mechanicscalculation model of gob-side entry retaining, provide the scientific basis for supportingdesign of gob-side entry retaining;(2) Based on the fully mechanized working face of cable anchor combinedsupporting roadway caving characteristics and basic bursting analysis fault of the basiclaw, that the equilibrium structure of roadway of fully mechanized working face abovethe basic roof and overlying strata caving of along goaf in fully mechanized miningstructure of surrounding rock of roadway, and keep on the top rope combined directlycantilever retaining formed under oblique cross beam is a beam or along goaf in fullymechanized small structure in the anchor net, large structure surrounding rock isdetermined along goaf in fully mechanized mining stability of spatial factors, by thestructure of rotary impact process sinking does not affect the overall instability ofsurrounding rock in mining, and maintained along the goaf stability is the smallstructure of surrounding the reasonable support, but also the key to the success or failureof the roadway along gob.(3) Numerical simulation analysis is respectively carried out for the each scheme using the numerical analysis software UDEC, the deformation of surrounding rock ofthe five supporting scheme is obtained, and the best one is determined.(4) Gob gob side roadway side body is to have a certain strength, but also have acertain deformation capacity, using concrete brickwork wall for roadside support has theadvantages of fast solidification, high strength, good stability, can meet the workingresistance enough in a short time. The roadway along goaf roadway initial support formachining steel cable anchor combined support; roadside roof with prestressed anchorstrengthening support, retaining walls on both sides of the use of single prop temporarysupport; roadside packing body uses the high strength concrete prefabricated blockbrickwork wall, reserve certain deformation is not connected with the top; ahead of theworking face is20m, the single hydraulic prop with H-shaped steel beam reinforcement.(5) Through the use of single hydraulic prop temporary support in the roadside,effectively cutting top, initial monomer hydraulic prop and roadside cable togetherprovide support resistance, effective control of the immediate roof separation andcutting off some direct top height, the roof subsidence reached pre shrinking, fillingbody start to load, to provide support resistance, maintain the surrounding rockstability;in the rear of the working face60m range safety to the cancellation prop andtemplates, to further improve the economic benefit.