摘要
为了分析水力割缝(冲孔)瓦斯高效抽采工艺中多缝槽布置对增透机制的影响,基于岩样单轴压缩数字散斑实验与颗粒流PFC模拟岩样变形的一致性验证,采用PFC模拟单轴加载下3缝槽煤岩试样力学损伤行为,分析缝槽中心连线与水平面夹角θ、缝槽分布水平对试样强度、裂纹发育以及裂纹扩展的影响,探讨缝槽分布方式对煤层增透作用特点,并通过实验室岩样声发射实验对模拟结果进行验证。分析结果表明,采用PFC开展岩样变形模拟是可行的,缝槽分布方式会显著影响试样的损伤特性,缝槽间夹角θ呈锐角时,试样更易破坏且裂纹更易萌生发育,缝槽分布水平增加将不利于裂纹发育,夹角0°<θ<90°时,可增大缝槽间影响范围,夹角θ为90°且缝槽面与主应力平行分布时,非常不利于煤层切槽增透作用。
In order to analyze the influence of multi slot arrangement on the permeability enhancing mechanism of hydraulic slotting(punching) gas efficient extraction technology, the consistency verification experiment based on uniaxial compression digital speckle pattern experiment and particle flow PFC simulation of rock deformation was conducted. Based on the results of the consistency verification experiment, PFC was used to simulate the mechanical damage behavior of coal and rock samples with 3 slots under uniaxial loading. The influence of the angle between the central line of the slot and the horizontal plane and the distribution level of the slot on the strength, crack development and crack propagation of the specimen were analyzed. And the effect of slot distribution on coal seam permeability was studied. The simulation results are verified by acoustic emission experiment of rock samples in laboratory. The results showed that it is feasible to simulate rock deformation by PFC and the distribution of slots has a significant effect on the damage characteristics of the specimens. When the angle between the slots is acute, the specimen is more likely to be damaged and the cracks are more likely to sprout and develop. When the angle is between 0° and 90°,the influence range between the slots can be increased. When the angle is 90° and the fracture surface is parallel to the main stress, the permeability enhancement effect of coal seam grooving is not good.
作者
叶飞
沈春明
杨小彬
YE Fei;SHEN Chun-ming;YANG Xiao-bin(Beijing Academy of Emergency Management Science and Technology,Beijing 101101,China;Beijing Research Center of Urban System Engineering,Beijing 100035,China;School of Safety Engineering,China University of Mining and Technology,Xuzhou 221116,China;Mine Safety Branch,China Coal Research Institute,Beijing 100013,China;China University of Mining and Technology(Beijing),Beijing 100083,China)
出处
《煤炭工程》
北大核心
2021年第10期111-115,共5页
Coal Engineering
基金
国家自然科学基金资助项目(51704163)。
关键词
水力割缝
多缝槽增透
缝槽煤岩损伤
瓦斯抽采
hydraulic slotting
multi slot permeability enhancing
seam coal rock damage
gas extraction
