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针对短壁连采边角煤回收技术,为解决因留设的隔离煤柱连锁破坏,进而诱发关键层大面积失稳运动引发的冲击难题,在分析短壁连采技术覆岩关键层2种破断运动形式的基础上,以控制关键层大面积破断运动诱发冲击为原则,提出了“顶板全垮落短壁连采边角煤回收技术”:在首块段和第2块段间留设隔离煤柱,保证煤柱在首块段开采期间保持稳定有效支撑顶板,第2块段开采时煤柱破坏失稳诱发关键层破断充分运动,实现煤柱破坏与关键层破断运动间的耦合协调;其后各块段完全取消隔离煤柱,实现顶板运动沉降连续化。首块段长度应小于关键层初次破断步距,以防止关键层沿边界产生塑性铰接线而处于临界不稳定状态;从煤柱弹塑性分区观点出发,分析了煤柱塑性破坏宽度及保持煤柱稳定的最小临界弹性宽度,建立煤柱合理宽度判据。
In order to solve the impact problem caused by the interlocking failure of the isolated pillars in the short-wall continuous mining, and then induce the impact caused by the large-area destabilizing movement in the key layer, two key strata- Based on the principle of breaking the motion form and controlling the large-area breaking motion-induced impact of the key layer, the paper puts forward the technology of “full roof caving shortwall with coal mined edge coal recovery”: between the first block and the second block Leaving the separation of pillars to ensure that the pillars in the first block during the mining period to maintain a stable and effective support roof, the second block mining failure of coal pillar instability induced fracture of the critical layer full movement to achieve the destruction of coal pillars and key layer between the breaking motion Coupling and coordination; Afterwards, the coal pillars are completely removed from each block to realize continuous roof settlement. The length of the first block should be less than the initial breaking step of the key layer to prevent the critical layer from being in a critical unstable state along the boundary due to the plastic hinge line. Based on the elastic-plastic zoning of coal pillars, the plastic rupture width of the coal pillar and the coal pillar Stable minimum critical elastic width, the establishment of coal pillar reasonable width criterion.