Evolution Law of Hard Roof Fracture in Different Mining Spaces of Coal Mine

BU Tengteng; YANG Shuhao; NING Jianguo; WANG Jun

doi:10.16545/j.cnki.cmet.2025.06.009

Abstract：Aiming at the problem that the evolution law of hard roof breaking under different mining spaces is not clear,multiple mining faces in a mining area of 11 coal seam in a coal mine were taken as the engineering background,and uses the combination of microseismic monitoring and theoretical deduction to analyze the breaking characteristics of hard roof under different mining spaces.The evolution model of roof breaking was constructed,and the atypical breaking mechanism of hard roof under different mining spaces was obtained.The results showed that with the expansion of mining space,the strength of ground pressure in the mining space decreased during the first weighting period.At the same time,the breaking span of the high hard roof decreases and finally breaks synchronously with the lower basic roof,which is also the reason for the decrease of the strength of ground pressure,under the mechanical environment of four-side fixed support,especially when the inclined span is small,the ultimate bearing capacity of the roof is large and the breaking span is large.In the mechanical environment of three sides fixed and one side simply supported,the increase of the inclined span destroys the bearing capacity of the roof,which leads to the decrease of the strike breaking span of the high hard roof.The research results provide a theoretical basis for the safe and efficient mining of deep mines.