Scholarlink

<p>The geostress and rock blasting in underground engineering may greatly affect the stress thresholds of surrounding rock. In this study, pre-damage impact tests were first conducted on granite under varying confining pressures (5, 10 and 15 MPa) and numbers of impacts (1, 5, 10 and 15 impacts). Then, uniaxial compression tests were undertaken on the pre-damaged granite to study the evolution of stress thresholds using the crack volume strain method and acoustic emission method. The crack damage stre0sses determined by the two methods were compared. Additionally, based on the rise time amplitude and average frequency, the evolution law of microcracks inside rock specimens was revealed, and an improved acoustic emission method was proposed. The results indicated that as the number of impacts increased, the crack closure stress, crack damage stress, and peak stress of granite specimens initially rose and then declined, while they continuously increased with the confining pressure. The proportion of shear cracks first declined and then rose with greater number of impacts and decreased with higher confining pressure, and that of tensile cracks showed the opposite trend. The improved acoustic emission method was more accurate in identifying the crack damage stress.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Characteristics of stress thresholds of granite after triaxial dynamic impact treatment

  • 期刊论文

  • 发表日期：

    2025年7月1日

查看全文
  • Kang Peng,
  • Xu Liu,
  • Xu-yan Yin,
  • Yun Zhang,
  • Yang-kai Chang,
  • Song Luo

摘要

The geostress and rock blasting in underground engineering may greatly affect the stress thresholds of surrounding rock. In this study, pre-damage impact tests were first conducted on granite under varying confining pressures (5, 10 and 15 MPa) and numbers of impacts (1, 5, 10 and 15 impacts). Then, uniaxial compression tests were undertaken on the pre-damaged granite to study the evolution of stress thresholds using the crack volume strain method and acoustic emission method. The crack damage stre0sses determined by the two methods were compared. Additionally, based on the rise time amplitude and average frequency, the evolution law of microcracks inside rock specimens was revealed, and an improved acoustic emission method was proposed. The results indicated that as the number of impacts increased, the crack closure stress, crack damage stress, and peak stress of granite specimens initially rose and then declined, while they continuously increased with the confining pressure. The proportion of shear cracks first declined and then rose with greater number of impacts and decreased with higher confining pressure, and that of tensile cracks showed the opposite trend. The improved acoustic emission method was more accurate in identifying the crack damage stress.