力学与实践 ›› 2021, Vol. 43 ›› Issue (2): 244-251.DOI: 10.6052/1000-0879-20-433

• 应用研究 • 上一篇    下一篇

基于Voronoi模型的脆性岩石微观结构数值模拟 1)

邱鑫*,†, 林缅*,†,2)(), 郑思平*,†, 陈天宇**   

  1. *中国科学院力学研究所,北京 100190
    †中国科学院大学,北京 100049
    **东北大学深部金属矿山安全开采教育部重点实验室,沈阳 110819
  • 收稿日期:2020-10-12 修回日期:2021-01-19 出版日期:2021-04-20 发布日期:2021-04-20
  • 通讯作者: 林缅
  • 作者简介:2)林缅,研究员,主要研究方向为非常规油气勘探开发。E-mail: linmian@imech.ac.cn
  • 基金资助:
    1)国家自然科学基金重点项目(42030808);国家自然科学基金重大项目(41690132);中国科学院战略性先导科技专项(XDA14010304);国家自然科学基金面上项目(41872163)

NUMERICAL SIMULATION OF BRITTLE ROCK MICROSTRUCTURE USING A VORONOI MODEL 1)

QIU Xin*,†, LIN Mian*,†,2)(), ZHENG Siping*,†, CHEN Tianyu**   

  1. *Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
    †University of Chinese Academy of Sciences, Beijing 100049, China
    **Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines, Northeastern University, Shenyang 110819, China
  • Received:2020-10-12 Revised:2021-01-19 Online:2021-04-20 Published:2021-04-20
  • Contact: LIN Mian

摘要:

基于离散元软件UDEC中的Voronoi模型,构建了致密岩石的标准压缩数值试件;应用FISH语言编译相关程序,监测不同脆性致密岩石的裂纹数量和密度在压缩过程中的变化特征。研究发现,随着岩石脆性指数的增加,岩石的起裂应力逐渐增加,而起裂点裂纹密度逐渐减小,高脆性岩石则是在较高的应力状态和较低的裂纹损伤状态下达到裂纹起裂点。岩石的峰值应力随着脆性指数的增加而增加,峰值点裂纹密度和脆性指数符合一拟合公式,根据该公式可以对峰值应力处岩石的裂纹损伤程度进行估计。可以把脆性指数0.6作为区分页岩脆性的经验值。

关键词: 离散元方法, Voronoi模型, 脆性岩石, 岩石微结构, 裂纹密度

Abstract:

Numerical compression specimens with different brittleness are constructed based on the UDEC-Voronoi model. The number of cracks and the crack density are monitored by the FISH programs. It is shown that the crack initiation stress increases with the increase of the brittleness index. However, the crack density at the crack initiation stress decreases. That is to say, the crack initiation of high brittle rocks is at a higher stress and with a fewer cracks as compared with the low brittle rocks. Furthermore, the peak stress increases as the brittleness index increases. A fitting formula is established to estimate the crack density at the peak stress against the brittleness index, and the brittleness index 0.6 can be used as an empirical value for judging the shale brittleness.

Key words: distinct element method, Voronoi model, brittle rocks, rock microstructure, crack density

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