采矿与安全工程学报 ›› 2013, Vol. 30 ›› Issue (2): 267-272.

• 论文 • 上一篇    下一篇

煤质页岩压缩变形特性及损伤破坏辨识试验研究

  

  1. 重庆大学煤矿灾害动力学与控制国家重点试验室,复杂煤气层瓦斯开采国家地方联合工程实验室,重庆  400044
  • 收稿日期:2012-04-11 出版日期:2013-03-15 发布日期:2013-02-24
  • 作者简介:王景环(1980-),男,江西省抚州市人,博士,从事页岩气开采方面的研究。 E-mail:wangjinghuan_000@sian.com Tel:023-65106640
  • 基金资助:

    中央高校基本科研业务费科研专项自然科学类项目(CDJZR10248801)

Research on properties of coaly shale compression deformation and its damage identification

  • Received:2012-04-11 Online:2013-03-15 Published:2013-02-24

摘要: 为了探索煤质页岩的压缩变形及损伤破坏特性,利用MTS岩石材料力学试验机,得到了煤质页岩的单轴和三轴压缩试验曲线,研究了单轴三轴压缩全过程中页岩损伤软化特征的异同;在此基础上,研究分析了页岩压缩过程中外力功、能量耗散以及能量释放机理,结合页岩特性和岩石强度破坏理论,建立了基于能量原理的页岩损伤演化本构方程:① 单轴应力状态下,页岩损伤全过程可用能量原理损伤本构方程模拟;② 三轴应力状态下,当轴向应力小于围压时,页岩本构关系可近似用线性方程模拟;当轴向应力大于围压时,应用基于能量原理损伤本构方程进行模拟。模型与试验结果对比分析显示,所建的模型力学参数简单,物理参数意义明确,能充分描述页岩单轴应变软化及三轴应变硬化阶段变形特征。

关键词: 煤质页岩, 压缩曲线, 能量原理, 损伤变量, 本构方程

Abstract: In order to explore properties of coaly shale compression deformation and its damage identification, by using the mechanical testing & a simulation system, the uniaxial and triaxial compression curves of coaly shale were obtained and their difference of damage softening properties was analyzed. Based on these, the mechanism of external work,energy dissipation,energy release were studied. Meanwhile, a damage formulation based on energy principle was deducted according to shale mechanics characteristic and rock strength and failure theory.① The resultant constitutive model based on energy principle can be used to simulate the damage of shale under uniaxial compression.② Under the condition of triaxial compression, the constitutive model of shale can be simulated by linear equation (or constitutive equation based on energy principle) when the axial stress is less (or more) than confining pressure. The comparison between the model and the experiment results shows that the mechanical parameters of model are simple and its physical parameters clear. It can also reflect deformation characteristics of softening under uniaxial compression and hardening under triaxial compression.

Key words: coaly shale, compression curve, energy principle, damage variable, response equation