长江科学院院报 ›› 2023, Vol. 40 ›› Issue (2): 115-123.DOI: 10.11988/ckyyb.20210927

• 岩土工程 • 上一篇    下一篇

不同温度条件下北山花岗岩巴西劈裂试验裂隙扩展过程

贺琦1,2, 陈世万1,2,3, 杨福波1,2, 田云雷1,2   

  1. 1.贵州大学 资源与环境工程学院,贵阳 550025;
    2.贵州大学 喀斯特地质资源与环境教育部重点实验室,贵阳 550025;
    3.中国科学院武汉岩土力学研究所 岩土力学与工程国家重点实验室,武汉 430071
  • 收稿日期:2021-09-01 修回日期:2022-01-24 出版日期:2023-02-01 发布日期:2023-03-07
  • 通讯作者: 陈世万(1990-),男,四川达州人,副教授,博士,研究方向为高放废物地质处置中岩石力学问题。E-mail:swchen@gzu.edu.cn
  • 作者简介:贺 琦(1997-),男,湖南长沙人,硕士研究生,主要从事热-力作用下花岗岩破裂方面的研究。E-mail:a854261022@163.com
  • 基金资助:
    国家自然科学基金项目(41902301);岩土力学与工程国家重点实验室开放基金课题(Z018023)

Crack Propagation of Beishan Granite under Brazilian Splitting Test at Different Temperatures

HE Qi1,2, CHEN Shi-wan1,2,3, YANG Fu-bo1,2, TIAN Yun-lei1,2   

  1. 1. College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China;
    2. Key Laboratory of Karst Georesources and Environment of Ministry of Education,Guizhou University, Guiyang 550025,China;
    3. State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China
  • Received:2021-09-01 Revised:2022-01-24 Online:2023-02-01 Published:2023-03-07

摘要: 对我国高放废物地质处置地下实验室场址的甘肃北山花岗岩分别进行不同温度下(25、60、90、120、200、300 ℃)的巴西劈裂试验,通过实时声发射监测、主断面分析以及颗粒流程序数值模拟,研究了岩样的裂隙扩展过程。结果表明:①120 ℃时温度对花岗岩存在显著强化效应,其他温度下花岗岩强度较常温下降低;②声发射数据显示中等温度(60~120 ℃)荷载下花岗岩产生的裂隙数量和尺度随着温度升高而增大,因此消耗更多的加载能量,使得花岗岩强度逐渐增大;③受长石、石英和云母的热力学性质差异影响,在室温至120 ℃范围,花岗岩断面裂隙随着温度升高更趋于沿着长石颗粒的边界扩展,120 ℃后非长石颗粒边界的裂隙占比开始上升;④基于花岗岩表面矿物实际分布建立了PFC2D模型并进行模拟试验,可知温度能降低矿物颗粒间的粘结强度,使得岩石更易发生破裂。

关键词: 北山花岗岩, 巴西劈裂试验, 温度, 裂隙, 声发射, K均值聚类法, PFC2D

Abstract: Brazilian splitting tests were conducted on Beishan granite (the potential host rock for China’s high-level radioactive waste repository) at different temperatures (25 ℃,60 ℃,90 ℃,120 ℃,200 ℃,and 300 ℃).The cracking process of granites was investigated using acoustic emission (AE),section analysis and particle flow code (PFC).Results reveal that:1) Temperature at 120℃ has a significant strengthening effect on granite,while the strength of granite at other temperatures is lower than that at 25 ℃.2) The AE data shows that the number and size of cracks in granite both increase with rising temperature in mild temperature range (60 ℃~120 ℃),which consumes more energy produced by loading and gradually improves the strength of granite.(3) Affected by the differences in thermodynamic properties of feldspar,quartz and mica,cracks of granite tend to propagate along the boundary of feldspar with the increase of temperature between 25 ℃ and 120 ℃.When temperature is higher than 120 ℃,the proportion of cracks at the boundary of non-feldspar particles begins to rise.(4) PFC2D model was established based on the distribution of minerals on granite surface,and the simulation suggest that temperature could reduce the bond strength between mineral particles and makes the rock more prone to fracture.

Key words: Beishan granite, Brazilian splitting test, temperature, cracks, acoustic emission, K-means clustering, PFC2D

中图分类号: