摘要
坚硬顶板的破裂运动是诱发冲击地压等动力灾害的重要因素。采用理论分析、实验室试验、现场工程实践等方法,开展了朱仙庄矿变层间距坚硬顶板破裂致灾机制及分区控制研究。结果表明:该矿上覆五含岩层厚度大、强度高、完整性好,在发生破裂运动时具有强冲击风险性,并且该岩层沿工作面推进方向与煤层间距逐渐减小直至完全接触,顶板型冲击地压的风险逐渐增大。通过建立五含顶板初次破断与周期破断力学模型,并根据层间基岩厚度的变化将五含岩层的周期破断划分为“完全触矸”“部分触矸”与“完全悬空”3个阶段,厘清了五含岩层初次破断与周期破断不同阶段的断裂步距与能量积聚特征;为降低顶板型冲击事故的发生,在初次断裂期间五含岩层厚度应不超过36 m;在周期断裂期间五含岩层预裂高度应大于10 m。确定采用深孔爆破五含坚硬顶板,给出了炮孔施工布置方案,工程实践后工作面支架工作阻力仅占额定工作阻力的69.33%,巷道顶底板及两帮最大移近量仅分别为24.9 mm和18.6 mm,取得了良好的防冲效果。
The fracturing movement of hard roof is a critical factor inducing dynamic disasters such as rock burst.In this study,the disaster-causing mechanism and zonal control of hard roof with varying lay-er spacing in Zhuxianzhuang Coal Mine were researched by means of theoretical analysis,laboratory ex-periments,and field engineering practice,and the following conclusions were drawn.The Wuhan roof stratum is characterized by large thickness,high strength,and good integrity,posing a considerable rock burst risk during fracturing movement.Additionally,the distance between this stratum and the coal seam gradually decreases along the working face advance direction until they are in full contact,which marks a growing risk of roof-type rock burst.Firstly,mechanical models for the initial fracturing and periodic fracturing of the Wuhan roof stratum were constructed,and its periodic fracturing was divided into three stages,i.e.,“full contact with gangue”“partial contact with gangue”aand“fully suspended”,according to the thickness variation of interlayer bedrock.On this basis,the fracturing steps and energy accumulation characteristics of the Wuhan roof stratum in different stages of initial fracturing and periodic fracturing were clarified.To reduce the occurrence of roof-type rock burst accidents,the thickness of the Wuhan roof stratum should not exceed 36 m during initial fracturing,and the pre-splitting height should exceed 10 m during periodic fracturing.Deep-hole blasting was implemented to fracture the Wuhan hard roof,and a construction layout plan for blast holes was provided.After engineering practices,the working resistance of the face support accounts for only 69.33%of the rated working resistance,and the maximum roof-floor and rib convergences are only 24.9 mm and 18.6 mm,respectively,that is,effective rock burst prevention has been achieved.
作者
王君
刘怀东
刘长友
王飞
赵波智
朱卫兵
张涵锐
WANG Jun;LIU Huaidong;LIU Changyou;WANG Fei;ZHAO Bozhi;ZHU Weibing;ZHANG Hanrui(State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources,China University of Mining and Technology,Xuzhou,Jiangsuu 221116,China;The Third Geological Brigade of Zhejiang Province,Jinhua,Zhejiang 321000,China)
出处
《采矿与安全工程学报》
北大核心
2025年第4期879-889,共11页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(52074267)。
关键词
变层间距顶板
坚硬顶板
冲击地压
能量积聚
深孔爆破
roof with varying interlayer spacing
hard roof
rock burst
energy accumulation
deep-hole blasting
