长江科学院院报 ›› 2020, Vol. 37 ›› Issue (1): 130-136.DOI: 10.11988/ckyyb.20180911

• 岩土工程 • 上一篇    下一篇

含裂隙大理岩的破碎演化和能量耗散研究

黄丹, 李小青, 邹锦洲, 宋文超   

  1. 华中科技大学 土木工程与力学学院, 武汉 430074
  • 收稿日期:2018-08-22 出版日期:2020-01-01 发布日期:2020-01-21
  • 作者简介:黄 丹(1986-),女,湖北仙桃人,助理研究员,博士,主要从事岩石及岩体力学特性方面的研究。E-mail:303374142@qq.com
  • 基金资助:
    国家自然科学基金项目(51278391)

Crack Evolution and Energy Dissipation of Marble Containing Flaws

HUANG Dan, LI Xiao-qing, ZOU Jin-zhou, SONG Wen-chao   

  1. School of Civil Engineering and Mechanics, Huazhong University of Science and Technology,Wuhan 430074, China
  • Received:2018-08-22 Online:2020-01-01 Published:2020-01-21

摘要: 岩石中裂隙分布对岩石的宏-微观力学性质和微裂纹的发育演化规律具有重要的影响。通过离散元方法(DEM),采用光滑节理模型建立不同裂隙倾角的模型进行单轴压缩试验,详细研究了大理岩在压缩过程中应力-应变特征、微裂纹发育演化过程、微观尺度上的能量耗散分配机制。结果表明:裂隙倾角与模型的应力-应变具有相关性,也影响微裂纹的发育演化过程;当裂隙倾角较小时,在达到峰值强度之前就产生了可见的拉裂纹,达到峰值强度之后拉裂纹继续增长并出现其他宏观裂缝;裂隙倾角较大时,达到峰值强度之前所产生的微裂纹大多零星分布,达到峰值强度之后微裂纹快速增加,形成多条裂缝。能量耗散研究表明:岩石的能量主要通过颗粒黏结存储于弹性势能中;在压缩过程中,弹性势能会缓慢降低并转变为摩擦耗能、阻尼耗能及破裂耗能,而破坏时4种能量占比大致相当。研究成果可为揭示裂隙岩石在压缩作用下裂纹扩展的细观力学响应机制提供参考。

关键词: 大理岩, 断续裂隙, 裂纹演化, 能量耗散, 裂隙倾角

Abstract: The distribution of flaws in rock has evident influence on the macro-and-microscopic mechanical properties and the evolution of microcracks of rocks. The smooth joint model was adopted to establish the rock model with different inclination angles based on the discrete element method (DEM) for uniaxial compression test. The stress-strain characteristics, microcracks development, distribution of energy dissipation in microscopic scale in the process of compression are studied. Results imply that the inclination angle of flaw is correlated with the stress-strain of the model, and also affects the evolution of microcracks. When the inclination angle of flaw is small, visible tensile cracks develop before peak strength is reached, and the cracks continue to grow after peak strength and other macroscopic cracks appear. On the contrary, when the inclination angle of flaw is large, the microcracks are mostly scattered before the peak strength, and surged to multiple cracks after the peak strength. Energy dissipation rule shows that the energy of rock is mainly stored in elastic energy through parallel bond. In the process of compression, the elastic energy decreases slowly and turns into frictional energy, damping energy and fracture energy. The proportions of such four kinds of energy are roughly equal at failure.

Key words: marble, pre-existing flaw, evolution of crack, energy dissipation, inclination angle of flaw

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