关键词: 软弱煤层, 强动压, 沿空掘巷, 窄煤柱, 非对称控制

Abstract: In response to the problem of large-scale instability and damage caused by coal pillars and surrounding rock support systems of the gob-side entry driving surrounding rock in deep weak coal seams with strong dynamic pressure, the deep horizontal coal roadway of Dongpang Mine is taken as the research object to reveal its failure mechanism; The theoretical analysis method was used to obtain the location of the fault line of the overlying basic roof strata, and the numerical relationship between the size of the coal pillar and the internal and external stress fields, as well as the width of the limit equilibrium zone, was clarified; By introducing the deviatoric stress analysis index, the response characteristics of the deviatoric stress and plastic failure field of the surrounding rock of the roadway under different coal pillar widths were studied. The reasonable width of the narrow coal pillar in the gob-side entry driving of deep strong dynamic pressure weak coal seams was determined to be 7 meters. Based on the width of a 7 m coal pillar, the distribution of deviatoric stress and plastic zone in the surrounding rock of the roadway at different positions of the advanced working face during mining was simulated and studied, and the strengthening range of individual pillars in the advanced working face was determined; Obtained the degree of plasticization of the roof, solid coal, and coal pillar walls after stable excavation, as well as the boundary line position of the peak stress zone; It is clarified that the coal pillar side of the gob-side entry driving is the key area for surrounding rock control. This paper elaborates on the control measures for surrounding rock when designing support, which require the anchor cable to pass through the boundary line of the peak stress zone of the surrounding rock and be within the relatively complete elastic zone in the deep part of the surrounding rock. A comprehensive treatment technology for surrounding rock is proposed, which includes “asymmetric channel steel truss anchor cable network on the side of the roadway + roof channel steel truss anchor cable joint point anchor cable + local fracture zone grouting modification + single hydraulic support advanced support”. Engineering practice has shown that the comprehensive treatment technology for the 7m wide coal pillar and surrounding rock support technology determined by the research can effectively ensure the safe recovery of the deep strong dynamic pressure weak coal seam working face.