Mechanism of strong strata behaviors during the working face out of the upper dip coal pillar in contiguous seams
JU Jin-feng
XU Jia-lin
ZHU Wei-bing
WANG Xiao-zhen
Abstract：Aiming at the problem of the strong strata behaviors during the No. 21305 working face out of the upper dip coal pillar in Huojitu Coal Mine of Daliuta, the mechanism and law of the problem were researched based on the stability analysis of the key block structure above the coal pillar and physical simulation. The research results indicate that the three hinged structure of key blocks above the coal pillar is unstable which results to the relative rotary motion of the two key blocks with the subsidence of the under strata. As a result, the fault block structure will lose its stability due to the excessive load. This is the fundamental source for the problem. Generally the turning angle of the two key blocks can not reach the extreme condition to maintain the structure' s stability, which leads to the universality of the strong strata behaviors during the working face out of the upper dip coal pillar. When the fracture line of the key block structure is in the outside of the pillar's boundary, the moment of the holding power to the structure is the least. Therefore the load on the under seam key strata will be the largest, which leads the problem of the strong strata behaviors mostly.
Keywords：dip coal pillarstrong strata behaviorkey blockkey stratumposition of fracture line
Publication Date：2010-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 15-20 )