1. School of Resource and Safety Engineering,China University of Mining and Technology( Beijing),Beijing　 100083,China; 2. Coal Industry Engineering Research Center of Top-coal Caving Mining,Beijing　 100083,China

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。

The support and surrounding rock relationship is affected by the loose top-coal in longwall top-coal caving mining (LTCC). The dynamic load tests under different particle types,particle sizes,particle packing thicknesses and impact forces were carried out by using the self-developed dynamic load impact test device,and revealed the influence of loose top-coal in LTCC on supports and surrounding rock relationship. It was found that the buffer effect is positively correlated with the particle packing density,that is to say,the buffer effect is more obvious with the larger particle packing density;when the packing thickness is less than a critical value,the impact effect is more obvious with the smaller packing thickness,on the contrary,the impact force gradually decreases then to be stable with the increment of packing thickness;though the effect of buffering dynamic load becomes greater with the increase of particle sizes,the buffer curve fluctuates obviously,which indicates that the impact process is severe. At the same time,the factors such as the condition of coal seam,the properties of loose top-coal and the structure performance of support should be con- sidered in selecting support type,so as to ensure the safe mining.

国家自然科学基金资助项目(51574244；51674264；U1361209)；

YANG Shengli,LI Zhaoxin,WEI Weijie,et al. Influence of loose top-coal on support and surrounding rock relationship in longwall top-coal caving mining[J]. Journal of China Coal Society,2017,42(10):2511-2517.