综放开采散体顶煤对支架与围岩关系影响的实验研究

发布时间：2019-01-07 12:22

【摘要】：散体顶煤的存在会改变综放开采支架与围岩相互作用关系。自主设计了散体动载荷冲击实验平台,对不同散体颗粒种类、不同颗粒大小、不同堆积厚度以及不同冲击力条件下进行动载冲击实验,揭示了散体顶煤对综放开采支架与围岩作用关系的影响。研究发现:散体密度与缓冲效果存在正相关,散体顶煤的堆积密度越大,散体缓冲上部动载荷效果越明显;散体堆积厚度变化存在临界值,当堆积厚度小于临界值时,破碎岩石堆积厚度越小冲击效果越明显,相反冲击压力随着堆积厚度的增加逐渐减小而后趋于不变;散体粒径越大,岩石缓冲上部动载荷效果越明显,但缓冲曲线的波动性较大,表明冲击过程比较剧烈。同时,提出了在支架选型时,要综合考虑煤层赋存条件、破碎顶煤性质及支架结构性能等因素,以保证放顶煤安全开采。
[Abstract]:The existence of granular top coal will change the interaction between support and surrounding rock in fully mechanized caving mining. In this paper, a dynamic impact test platform is designed. The dynamic impact test is carried out under the conditions of different particle types, different particle sizes, different stacking thickness and different impact forces. The influence of loose top coal on the relationship between support and surrounding rock in fully mechanized caving mining is revealed. It is found that there is a positive correlation between the bulk density and the buffer effect. The bigger the bulk density is, the more obvious the dynamic load effect is. There is a critical value in the variation of bulk deposition thickness. When the accumulation thickness is less than the critical value, the smaller the thickness of the fractured rock is, the more obvious the impact effect is, on the contrary, the impact pressure decreases gradually with the increase of the accumulation thickness and then tends to remain unchanged. The larger the particle size is, the more obvious the effect of dynamic load on the upper buffer of rock is, but the fluctuation of the buffer curve is larger, which indicates that the impact process is more severe. At the same time, some factors such as coal seam occurrence condition, broken top coal property and support structure performance should be taken into account in the selection of support, so as to ensure the safe mining of top coal caving.
【作者单位】：中国矿业大学(北京)资源与安全工程学院;放顶煤开采煤炭行业工程研究中心;
【基金】：国家自然科学基金资助项目(51574244,51674264,U1361209)
【分类号】：TD323

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