Experimental Study on Properties of Rock-Cemented Coal Gangue-Fly Ash Backfill Bimaterials with Different Coal Gangue Particle Sizes
Experimental Study on Properties of Rock-Cemented Coal Gangue-Fly Ash Backfill Bimaterials with Different Coal Gangue Particle Sizes
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不同煤矸石粒径胶结煤矸石-粉煤灰回填双材料性能试验研究
DOI：
10.1155/2020/8820330
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发表时间：
2020-09
影响因子：
1.8
通讯作者：
Yanhua Sun
中科院分区：
文献类型：
--
作者：
Yabo Wang;Dawei Yin;Shaojie Chen;Libo Zhang;Dongyi Liu;Yanhua Sun
煤矸石-粉煤灰胶结充填双材料的性能决定了煤矸石-粉煤灰胶结充填条带开采控制地表沉陷的效果，而煤矸石-粉煤灰胶结充填双材料中煤矸石的粒径又影响着煤矸石-粉煤灰胶结充填条带开采控制地表沉陷的效果。通过单轴压缩试验，研究了不同煤矸石粒径的粗砂岩-CGFB复合试样的强度、声发射和破坏特征。复合试样的单轴抗压强度和弹性模量随煤矸石粒径的增大而减小。复合试样的强度主要取决于其中CGFB的强度，并受CGFB与粗砂岩之间相互作用的影响。粗砂岩的变形削弱了粗砂岩中的损伤积累，导致复合试样的强度大于粗砂岩。煤矸石粒径为0 ~ 5 mm、5 ~ 10 mm和10 ~ 15 mm的复合试样的抗压强度平均值分别比普通粉煤灰提高了10.78%、14.98%和12.70%。将复合样本的声发射事件信号规律分为三个阶段：上升期、平静期和活跃期。随着煤矸石粒径的增大，声发射信号的强度和频率在三个时间段内都有所增强。平静期可以作为复合试样在荷载作用下破坏失稳的重要信息，其持续时间随煤矸石粒径的增大而变短。粗砂岩的回弹变形引起了活动期后期AE事件信号的波动。复合试样的破坏主要发生在粗砂岩中，粗砂岩中未发现明显的破坏。CGFB主要发生劈裂破坏，并伴有不同程度的表层剥落破坏。随着煤矸石粒径的增大，CGFB的破碎程度增大，破坏后CGFB碎片（屑）的最大重量比由煤矸石粒径决定。
Properties of rock-cemented coal gangue-fly ash backfill (CGFB) bimaterials determine the effects of strip CGFB mining on controlling the surface subsidence in coal mines, which are affected by the coal gangue particle size in CGFB. In this paper, uniaxial compression tests were conducted on the coarse sandstone-CGFB composite samples with different coal gangue particle sizes, and their strength, acoustic emission (AE), and failure characteristics were investigated. The uniaxial compressive strength (UCS) and elastic modulus of the composite sample decreased with the coal gangue particle size. The strength of the composite sample is mainly dependent on that of CGFB in it, affected by interactions between CGFB and coarse sandstone. The deformation of the coarse sandstone weakened the damage accumulation within CGFB, resulting in the strength of the composite sample larger than that of CGFB. The average UCS values of composite samples with coal gangue particle sizes of 0∼5 mm, 5∼10 mm, and 10∼15 mm, increased by 10.78%, 14.98%, and 12.70% compared with CGFB in them, respectively. AE event signal regularity of the composite sample was divided into three stages: rising period, calm period, and active period. The intensity and frequency of AE event signals in three periods were strengthened with the coal gangue particle size. The calm period can be taken as the precursory information for the failure and instability of composite sample under loading, whose duration became shortly with the coal gangue particle size. The rebound deformation of coarse sandstone caused the fluctuations of AE event signals at the later stage of active period. The failures of the composite sample occurred within CGFB, and no obvious failures were found in the coarse sandstone. The CGFB mainly experienced the splitting failure accompanying by varying degrees of surface spalling failures. The broken degree of CGFB increased with the coal gangue particle size, and the largest weight ratio of CGFB fragments (chips) after failure was determined by the coal gangue particle size.
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影响因子：
6.2
作者：
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DOI：
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影响因子：
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