基于关键层理论的切顶留巷下覆岩裂隙分布特征研究  

Characterization of fissure distribution of overburden rock under roof cutting and entry retaining based on key strata theory

作　　者：双海清 辛越强 李树刚 林海飞[1,2] 周斌 尚英智[3] 刘思博 SHUANG Haiqing;XIN Yueqiang;LI Shugang;LIN Haifei;ZHOU Bin;SHANG Yingzhi;LIU Sibo(College of Safey Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Key Laboratory of Western Mine Exploitation and Hazard Prevention,Ministry of Education,Xi’an University of Science and Technology,Xi’an 710054,China;Shaanxi Shuanglong Coal Industry Development Co.,Ltd.,Yan’an 727306,China)

机构地区：[1]西安科技大学安全科学与工程学院,陕西西安710054 [2]西部矿井开采及灾害防治教育部重点试验室,陕西西安710054 [3]陕西双龙煤业开发有限责任公司,陕西延安727306

出　　处：《煤炭科学技术》2024年第5期102-113,共12页Coal Science and Technology

基　　金：国家自然科学基金资助项目(51904238,52074217)。

摘　　要：针对切顶留巷工艺使得切顶侧采空区覆岩裂隙分布改变的问题,采用物理相似模拟与数值模拟相结合的手段分析了切顶留巷工艺下采空区应力分布、覆岩运移和采动裂隙分布规律。在此基础上,基于关键层理论与采动覆岩卸荷膨胀累积效应,探讨了切顶与未切顶侧覆岩裂隙发育高度和离层裂隙区宽度的变化,分析了不同层位定向卸压瓦斯抽采钻孔抽采效果,验证和反演了切顶留巷工艺下覆岩裂隙分布规律。研究结果表明:切顶留巷工艺能有效降低切顶侧顶底板的应力集中,但应力仍会向煤岩深部传递;切顶使得垮落岩层厚度与顶板破断形式发生改变,导致裂隙带发育高度、亚关键层控制范围内离层裂隙区宽度产生变化;切顶侧端头垮落带高度为未切顶侧的2倍,裂隙带高度为未切顶侧的0.87倍,在裂隙带中下部,切顶侧的离层量和穿层裂隙数量均大于未切顶侧;切顶侧在煤层顶板8~30 m范围内裂隙发育量随距离增大而增大,在30~48 m范围内随距离增大而减小,裂隙主要分布于裂隙带中下部;不同层位抽采钻孔瓦斯浓度和流量的“错峰”验证了上述研究结论。研究结果对高瓦斯矿井切顶留巷工艺下卸压瓦斯治理具有一定参考价值。Aiming at the problem of changing the distribution of overburden fissures in the overhead mining area due to the cutting and retaining roadway process,the stress distribution,overburden transport and mining fissure distribution law in the mining zone under the roof cutting and retaining roadway process were analyzed by means of a combination of physical similarity simulation and numerical simulation.On this basis,based on the key strata theory and the cumulative effect of unloading and expansion of mining overburden,the changes in the height of overburden fissure development and the width of fissure zones on the roof cutting and un-cutting sides were investigated,the extraction effect of the directional unloading gas extraction boreholes in different strata was analyzed,and the overburden fissure distribution law under the roof cutting and retaining roadway process was verified and inverted.The results shown that,the roof cutting and retaining roadway process can effectively reduce the stress concentration of the top and bottom plates on the roof cutting side,but the stress will still be transferred to the deeper part of coal.Roof cutting caused changes in the thickness of the collapsed rock layer and the form of roof breakage,which led to the changes in the height of the fissure zone development,and the width of the off-strata fissure zones within the sub-critical strata control range.The height of the collapsed zone on the roof cutting side was twice as much as that on the un-cutting side,and the height of the fissure zone was 0.87 times as much as that on the un-cutting side.In the middle and lower part of the fissure zone,the amount of off-strata and the number of penetrating fissures on the cut top side are larger than those on the uncut top side;the amount of fissure development on the roof cutting side were larger than those on the un-cutting side.The amount of fissure development on the coal seam roof of roof cutting side increased with the increasing distance in the range of 8−30 m,and decreased with t

关 键 词：瓦斯抽采 卸压瓦斯 切顶留巷 覆岩裂隙 覆岩累计膨胀 

分 类 号：TD712[矿业工程—矿井通风与安全]