Technology of Gateway Retained Along Goaf with Quick Setting Concrete Backilled at Gateway Sidewall in Underground Mine

According to the complicated geological conditions, deep mining depth, frequent coal mining face removing, high tension replacement of coal mining fac e and excavation face, mining in island seam face and other problems of a fully mechanized coal mining face in the deep section of Jining No.2 Mine, the paper studied the roof movement law of the gateway retained along goaf.The gateway retained along goaf technology mainly with quick setting concrete backfilled at the gateway side was applied.A numerical simulation analysis was conducted on the stress and deformation of the concrete wall at the side of the gateway retained along goaf.A design was conducted on the support parameters of the gateway side and the anchor reinforced support of the roof.In the transporation gateway of No.93A02 mining face, the t echnology was applied to the gateway retained along the goaf with a length of 870 m and the concrete wall was stable.After the rail gateway of No.93A03 mining face g ateway retained along goaf, the mine strata pressure observation results showed that the deformation of the gateway retained along the goaf was less than the coal pill ar protected gateway and the economic benefits were obvious.