Reasonable staggered distance of coal pillar in repeated mining area of contiguous seams

MAO Huajin

doi:10.11799/ce202405004

Abstract：In order to study reasonable stagger distance of coal pillar group in mining of contiguous seams,taking 8#and 11#coal seams of Ganzhuang Coal Mine in Shanxi as the research background,the mechanical calculation model of reasonable stagger distance of coal pillar group was constructed with theoretical calculation.The reasonable stagger distance of district coal pillar was studied using numerical simulation,and the scientific rationality of the research was verified by field application.The research shows that the stress disturbance area of the coal pillar group can be divided into three areas:stress concentration area,stress disturbance area and stress superposition area.The stress distribution range is affected by the stress transfer angle of the coal pillar,the interlayer spacing and the width of the upper coal pillar,and has a linear relationship with and a trigonometric function relationship with the stress transfer angle of the coal pillar.The interlayer spacing has the greatest influence on the SL value.According to the numerical simulation and theoretical calculation,the reasonable staggered distance of district coal pillar should be greater than 40 m.The YHY30 intrinsically safe borehole stress meter was used to monitor the field application.The monitoring data was similar to the theoretical analysis results,which verified the accuracy of this study.