含瓦斯煤剪切破裂过程细观演化

运用自主研发的煤岩细观剪切实验装置,开展了不同成型压力条件下含瓦斯煤剪切破裂过程研究。研究含瓦斯煤剪切破裂过程中微细观裂纹的开裂、扩展、贯通演化规律,对比分析成型压力对含瓦斯煤抗剪强度及剪切破裂最终形态的影响。研究发现：随成型压力增加含瓦斯煤密实度增大,抗剪强度增大;剪切破裂过程裂纹扩展速率与开裂位置偏离预定剪切面距离有关,预定剪切面上剪应力大扩展速率快,偏离预定剪切面扩展裂纹受力减小,扩展速率低,甚至会终止扩展而不能贯通;裂纹扩展形态与成型压力有关,成型压力小,密实度低,抗剪强度低,裂纹容易扩展,剪切带范围小,成型压力大,密实度高,抗剪强度高,裂纹不容易扩展,剪切带范围大;含瓦斯煤剪切破裂过...

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Bibliographic Details
Published in煤炭学报 Vol. 39; no. 11; pp. 2213 - 2219
Main Author 许江 冯丹 程立朝 张先萌 谭皓月 刘婧
Format Journal Article
LanguageChinese
Published 2014
Subjects
剪切
含瓦斯煤
成型压力
细观
雁行排列
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Summary:运用自主研发的煤岩细观剪切实验装置,开展了不同成型压力条件下含瓦斯煤剪切破裂过程研究。研究含瓦斯煤剪切破裂过程中微细观裂纹的开裂、扩展、贯通演化规律,对比分析成型压力对含瓦斯煤抗剪强度及剪切破裂最终形态的影响。研究发现：随成型压力增加含瓦斯煤密实度增大,抗剪强度增大;剪切破裂过程裂纹扩展速率与开裂位置偏离预定剪切面距离有关,预定剪切面上剪应力大扩展速率快,偏离预定剪切面扩展裂纹受力减小,扩展速率低,甚至会终止扩展而不能贯通;裂纹扩展形态与成型压力有关,成型压力小,密实度低,抗剪强度低,裂纹容易扩展,剪切带范围小,成型压力大,密实度高,抗剪强度高,裂纹不容易扩展,剪切带范围大;含瓦斯煤剪切破裂过程左侧固定右侧受剪切荷载作用,容易形成雁行排列,为实现最终贯通,破坏雁行排列之间会有张拉牵引裂纹产生。
Bibliography:coal containing gas; shearing; mesoscopic; molding pressure; echelon crack
11-2190/TD
XU Jiang,FENG Dan,CHENG Li-chao,ZHANG Xian-meng,TAN Hao-yue,LIU Jing （ 1. State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China ;2. State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam, Chongqing University, Chongqing 400044, China）
With the self-developed meso-shear test equipment for coal and rock shear fracture tests on coal containing gas were carried out under different molding pressures. The rules of the cracks＇ initiation,evolution and transfixion were studied at a mesoscopic level. Also different molding pressure impacts on shear strength and the final shear fracture were analyzed. The results suggest that the coal density and the shear strength increase with the increase of molding pressure. The speed of crack propagation is related to the distance between the predetermined shear plane and the cracking position. On predetermin
ISSN:0253-9993