Cracking Process and Stress Field Evolution in Specimen Containing Combined Flaw Under Uniaxial Compression

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• 作者：Ting Liu ; Baiquan Lin ; Wei Yang ; Quanle Zou…
• 刊名：Rock Mechanics and Rock Engineering
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：49
• 期：8
• 页码：3095-3113
• 全文大小：11,343 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Earth sciences
  Geophysics and Geodesy
  Civil Engineering
  
• 出版者：Springer Wien
• ISSN：1434-453X
• 卷排序：49

文摘

Hydraulic slotting, an efficient technique for underground enhanced coal bed methane (ECBM) recovery, has been widely used in China. However, its pressure relief mechanism is unclear. Thus far, only limited research has been conducted on the relationships among the mechanical properties, flaw parameters, and crack propagation patterns of coal after hydraulic slotting. In addition, because of the limitations of test methods, an in-depth information is not available for this purpose. In this work, numerical models of specimens containing combined flaws are established based on particle flow code method. Our results provide insights into the effects of flaw inclination angle on the mechanical properties, crack propagation patterns, and temporal and spatial evolution rules of stress field in specimens containing combined flaws during the loading process. Besides, based on the initiation position and underlying mechanism, three types of crack initiation modes are identified from the failure processes of specimens. Finally, the crack propagation pattern is quantitatively described by the fractal dimension, which is found to be inversely proportional to the uniaxial compressive strength and elastic modulus of the specimen. To verify the rationality of the numerical simulation results, laboratory tests were conducted and their results match well with those obtained from the numerical simulation.KeywordsMechanical propertiesCracking processStress field evolutionCombined flawsParticle flow code method