油气藏评价与开发 ›› 2024, Vol. 14 ›› Issue (6): 942-951.doi: 10.13809/j.cnki.cn32-1825/te.2024.06.016

• 综合研究 • 上一篇    下一篇

复杂方解石脉充填煤岩细观损伤演化特性研究

邬忠虎1(), 夏茜2, 王文涛1, 唐摩天3,4, 雷文丽1, 孟祥瑞1   

  1. 1.贵州大学土木工程学院,贵州 贵阳 550025
    2.永丰县综合交通运输事业发展中心,江西 吉安 343000
    3.中国电建集团中南勘测设计研究院有限公司,湖南 长沙 410014
    4.湖南中南水电水利工程建设有限公司,湖南 长沙 410014
  • 收稿日期:2023-08-22 发布日期:2024-12-10 出版日期:2024-12-26
  • 作者简介:邬忠虎(1989—),男,博士,教授,从事岩土体破裂失稳、储层裂缝预测及隧道与地下工程灾害防治研究工作。地址:贵州省贵阳市花溪区贵州大学,邮政编码:550025。 E-mail: wuzhonghugzu@163.com
  • 基金资助:
    国家自然科学基金项目“黔北下寒武统页岩多期裂缝形成机理及分布预测模型研究”(52104080);贵州省科技支撑计划项目“六盘水地区煤层气储层渗透机制及压裂缝网优化改造关键技术研究与示范”(2021401);贵州省科技计划项目“贵州省页岩气效益开发关键技术及工程试验”(2022ZD005)

Characterization of mesoscopic damage evolution in complex calcite vein-filled coal rocks

WU Zhonghu1(), XIA Xi2, WANG Wentao1, TANG Motian3,4, LEI Wenli1, MENG Xiangrui1   

  1. 1. College of Civil Engineering, Guizhou University, Guiyang, Guizhou 550025, China
    2. Yongfeng County Comprehensive Transportation Business Development Centre, Ji’an, Jiangxi 343000, China
    3. China Electric Power Construction Group Zhongnan Survey and Design Institute Co., Ltd., Changsha, Hunan 410014, China
    4. Hunan Zhongnan Hydropower and Water Conservancy Engineering Construction Co., Ltd., Changsha, Hunan 410014, China
  • Received:2023-08-22 Online:2024-12-10 Published:2024-12-26

摘要:

为探索单轴作用下煤岩内部方解石复杂形态的破坏特征,通过薄片观察煤岩内部方解石脉充填形态,采用分形维数来描述方解石形态的复杂程度,利用二维真实破裂过程细观分析软件对不同形态下的方解石煤岩进行了单轴压缩数值模拟实验。结果表明:方解石复杂程度对煤岩细观损伤演化特性极其敏感,峰值强度随着方解石分形维数的增大整体呈现增大的趋势;裂缝率和峰值应力二者呈正相关,最终破坏时产生的峰值强度越高,其对应的裂缝率也越高。此外在单轴压缩过程中,方解石脉颗粒周边首先出现很多微小裂缝,断裂延伸方向和方解石脉走向几乎一致,影响煤岩的裂缝延伸方向。分形维数越大,声发射计数数量越多,煤岩破坏也越复杂。研究成果有助于深入认识方解石脉分布形态对煤岩力学性质的影响,并为研究含方解石脉煤岩细观损伤演化规律提供了新的方法。

关键词: 煤岩, 细观, 方解石脉, 分形维数, 破坏

Abstract:

To investigate the failure characteristics of calcite veins with complex morphologies in coal rock under uniaxial compression, thin-section observation was used to examine the calcite vein filling within coal rock. Fractal dimension analysis was applied to quantify the complexity of calcite morphology. Numerical simulations of uniaxial compression tests on coal rock containing calcite veins of varying morphologies were conducted using a two-dimensional real failure process mesoscopic analysis software. The results revealed that the complexity of calcite morphology significantly affected the mesoscopic damage evolution characteristics of coal rock. The peak strength generally increased with the fractal dimension of the calcite veins. A positive correlation between crack rate and peak stress was observed, indicating that higher peak strengths corresponded to higher crack rates at final failure. During uniaxial compression, multiple microcracks initially appeared around the calcite vein particles, with fracture propagation directions closely aligned with the vein orientation, influencing the crack propagation direction in the coal rock. Additionally, coal rock with larger fractal dimensions exhibited more acoustic emission events, signifying more complex failure patterns. These findings contribute to a deeper understanding of how calcite vein distribution affects the mechanical properties of coal rock and provide a novel approach to studying the mesoscopic damage evolution in coal rock containing calcite veins.

Key words: coal rock, mesoscopic, calcite vein, fractal dimension, failure

中图分类号: 

  • TE37