Determining the optimum gateway location for extremely close coal seams
Abstract：Calculations were done to estimate the strain and stress distributions in the floor un- der a coal pillar left in an upper coal seam in close conjunction with an underlying seam. The Caocun coal mine number 10 and 11 seams were used as a basis for the model. The calculations predict that the maximum strain in the floor caused by the bearing pressure from the number 10 seam being mined is 26.1 m. This is 2.8 times the distance between seams. The stress distri- butions in the floor around the pillar are significantly non-uniform. The variation rate coeffi- cient in the stress fields was defined to evaluate this non-uniformity. A inner stagger distance for the gateway of the 209 work face in the number 11 seam was determined, a value of 7.5 m is reasonable for a 1.5 safety factor and an assumed uniform loading. Field studies show this stagger layout to be suitable and that the support from the gateway is improved and that strong pressures do not appear after mining.
Keywords：extremely close coal seamisland workfaceoptimum positioninner stagger dis-tancevariation rate coefficient in stress fields
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 182-188 )