大倾角煤层长壁大采高采场顶板稳定性及其与支架相互作用特征研究

The steeply dipping seam is defined by the coal seam a pitch between 35 -55 , the reserves account for approximately 15%-20% of the total coal reserves in China, and also nearly 50% of which is quality coking coal and anthracite. The large mining height method can raising steeply dipping coal mining rate, but the feature of unsymmetrical and non-integrity key stratum, sliding and filling of large scale failure rock is extremely complicated, and inducing more instability of "support-rock" system. By using synthesis research methods of theoretical analysis, experimental study, field test and practice around the working face area in complex occurrence conditions (different pitches and mining height), the unsymmetrical stress distribution and its evolution characteristic, and the instability mechanism of different key strata structure forms, and the stable control model of "roof-support" system affecting by deformation and failure of immediate roof is summarized. Studies on stability of the "support-roof" system around the mining face by using the large mining height method has great significance to enrich the practice and theory in mining the steeply dipping seam.

大倾角煤层是指埋藏倾角为35 ～55 的煤层。我国大倾角煤层约占有15％～20％的储量，50％以上的大倾角煤层为优质焦煤和无烟煤，是我国保护性开采的稀缺煤种，大采高开采方法可大大提高该类煤炭资源的采出效率，但大采高开采时采场顶板岩层中非对称且不完整的关键层空间结构特征和大尺度采空区破坏岩体滑移、充填特征较一般大倾角煤层机械化开采时要异常复杂，导致维持"支架-围岩"系统稳定性难度更大。采用"理论分析-实验研究-现场测试-工程实践"四位一体综合研究方法，系统研究大倾角煤层长壁大采高开采多因素（倾角、采高等）交互影响下采场围岩空间非对称应力场形成与演化机制、关键层岩体结构形成与失稳机制、顶板变形破坏作用下工作面"支架-围岩"系统动态稳定控制模式等科学问题，可为解决大倾角大采高工作面"顶板-支架"系统动态稳定性控制、围岩变形破坏与大范围运动控制等关键技术提供理论依据，且丰富了大倾角煤层开采理论。

大倾角煤层是埋藏倾角35°～55°的煤层，约占我国煤炭储量的15％～20％。大倾角煤层长壁大采高开采可显著提高该类煤炭资源的采出效率，文献检索表明，无国内外相关道，因此，亟需从岩层控制角度入手对该开采条件下“支架-围岩”系统稳定性进行深入研究。.采用理论、模拟实验和现场实测相结合研究方法，分析了大倾角煤层长壁大采高采场顶板稳定性及其与支架相互作用特征，结果表明，大倾角大采高采场围岩运移规律与一般采高大倾角煤层相似，具有明显非对称性，但大采高采场围岩运移特征更活跃，破断基本顶易形成反倾向堆砌结构，垮落顶板滚、滑、充填空间增大，采空区倾斜下部充填压实程度增加、充填长度减小，工作面顶板受力非均衡性更为明显。.采场顶板易形成跨层位、大尺度、非对称的空间梯阶状岩层结构，其中，高位梯阶岩层结构周期性破坏具有强度大、步距小、周期短、冲击强等特征，给出了高位梯阶岩体结构失稳判定准则，明确了该结构具有拉伸、压剪和复合型等失稳模式，可造成工作面倾斜上部支架受载多变、中上部高煤壁片帮等矿压现象。.不同层位梯阶岩层破坏形成的倾斜砌体结构具有“时间-空间”非均衡运动特征，给出了大尺度采场下不同类型结构与支架作用方式，得出了倾斜砌体结构造成支架发生挤压型失稳、下滑型失稳、倾倒性失稳和后推型破坏的判定准则，揭示了大尺度高位岩体结构失稳产生冲击性来压、低位岩体结构失稳导致推垮失稳致灾机理。从而为破解大倾角大采高开采岩层控制和装备制造关键技术奠定了理论基础。