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综放工作面过空巷矿压显现规律及控制技术研究

Study on ground pressure and control technology of a fully mechanized top coal caving longwall face passing a pre-driven roadway

  • 摘要: 通过数值模拟与理论分析等方法对工作面过空巷时超前应力分布、煤体稳定性及基本顶破坏特征进行研究,结果显示:超前应力叠加作用下空巷围岩变形剧烈,煤柱失稳破坏;基于Winkler弹性基础梁理论建立基本顶破断力学模型,求解了空巷上方基本顶弯矩方程,其揭示了空巷导致工作面前方基本顶超前断裂的现象,且空巷越宽,基本顶超前断裂位置离工作面越远;工作面推进过程中其前方基本顶偏应力第二不变量J2呈双峰值分布,工作面离空巷越近,基本顶J2峰值越高,畸变能越大。基于数值模拟研究工作面过空巷围岩控制技术,结果显示:高水材料充填支护空巷能有效避免基本顶超前断裂,维护空巷的稳定性。制定了高水材料充填与双木垛支护的空巷分区控制措施,现场监测显示:工作面过空巷过程中,液压支架工作阻力处在安全范围内,工作面能够安全通过空巷。该研究成果对同类型综放工作面过空巷期间巷道围岩与顶板控制可提供一定的参考。

     

    Abstract: By means of numerical simulation and theoretical analysis,this paper studies the front abutment pressure distribution,coal stability and the main roof failure characteristics when the working face passes through a pre-driven roadway.The results show that the surrounding rock of the pre-driven roadway is severely damaged due to the high front abutment pressure.The main roof breaking mechanical model was established based on Winkler elastic foundation beam theory,and the main roof bending moment equation above the empty roadway solved,which reveals the phenomenon that the roof of pre-driven roadway factures in front of the working face.The wider the pre-driven roadway is,the farther the main roof fracture of occurs in front of the working face.During the advancing process of the working face,the main roof deviatoric stress J2 in front of the working face presents a double peak distribution.The closer the working face to the pre-driven roadway,the higher the main roof J2 peak value and the greater the distortion energy.The numerical simulation suggests that high water material filling support can effectively avoid the main roof fracture in front of the working face and maintain the stability of the pre-driven roadway.The zoning controlmeasures for high water material filling and double timber crib support are formulated.Field monitored data shows that the working resistance of the hydraulic support is within the safe range during the process of the working face passing through the pre-driven roadway.The study provides a reference for the control of roadway surrounding rock and roof with a fully mechanized caving longwall face passes through a pre-driven roadway.

     

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