Rational Location and Support Technology of Mining Gateway in Seam with Ultra Closed Distance to Above Seam

Based on the maintenance difficultyt and high repair rate problems of the high pressurized mining gateway with a complex roof in a seam with ultra close d distance to the above seam,the paper proposed that the mining gateway in the below seam should have an internal offset layout.The sectional support,combined supp ort plan and support parameters of the mining gateway in the below seam with an ultra closed distance for different layer distance were determined.The results showed the mining gateway in the below seam would be internally offset located in a low stress zone.When the thickness of the seam roof was 1.84.0 m,the bolt+steel band was applied as the first support and the anchor+H steel beam applied as the second combined support of the roof.When the top of the roof was solid coal or goaf with a dist ance of 4.0 6.5 m,the bolt + steel band would be applied as the first support and the anchor + H steel beam would be applied as the second combined support.When the roof thickness was over 6.5 m or the top of the roof was solid coal,the bolt + steel band would be applied as the first support and the anchor would be applied to the sec ond combined support with a rational support effect.