Research Of Gob-side Entry Retaining Reasonable Support In Gently Inclined And Middle Thick Coal Seam

In the traditional coal mining, roadway maintenance often requires leaving in part of the coal pillar, which resulted in significant loss of coal resources. In order to rational exploit the coal resources, enhance the coal resources recovery, most coal mines in our country have to maintain roadway by gob-side entry retaining. Its advantages have reducing the amount of roadway excavation, reduced roadway excavation rate, improve roadway maintenance, significant of economic and technical benefits and so on. The successful of gob-side entry retaining lie in the choice of roadside support and entry-in support. So it's very important to research of the reasonable support in gob-side entry retaining.Based on the geological condition of fully-mechanized face in gently inclined and middle thick coal seam of Dazhu coal-electricity group, the supporting scheme of gob-side entry retaining in 3117 face of Jingang mine was compared, the rational and effective supporting scheme of gob-side entry retaining was obtained by using combined research of the theoretical analysis, the numerical analysis and the field measurement. There main search achievements are as follows:(1) Studied on the moving rule of surrounding rock and established mechanics calculation model of gob-side entry retaining, provide the scientific basis for supporting design of gob-side entry retaining.(2) Five supporting scheme was designed by study on the moving rule of surrounding rock and common way of roadside support and roadway support. Supporting scheme one: bolt-mesh-anchor support in roadway and dense pillar support in roadside; Supporting scheme two: bolt-mesh-anchor support in roadway and gangue support in roadside; Supporting scheme three: bolt-mesh-anchor support in roadway and filling common concrete to support in roadside; Supporting scheme four: bolt-mesh-anchor support in roadway and combined support common concrete and anchor cable in roadside; Supporting scheme five: bolt-mesh-anchor support in roadway and concrete block support in roadside.(3) Using the numerical analysis software UDEC which is suited to analyses rock stratum rupture and collapse, obtained the deformation of surrounding rock of the five supporting scheme. Determined use the supporting scheme three, four and five to field tests by comparison analysis. (4) According to field tests, ground pressure monitoring and economic analysis, the supporting scheme five which is bolt-mesh-anchor support in roadway and concrete block support in roadside is reasonable, effective and economical. Roadway can completely satisfy the needs of production in the next face after gob-side entry retaining.