<p>During underground excavation, the surrounding rock mass is subjected to complex cyclic stress, significantly impacting its long-term stability, especially under varying water content conditions where this effect is amplified. However, research on the mechanical response mechanisms of surrounding rock mass under such conditions remains inadequate. This study utilized acoustic emission (AE) and resistivity testing to monitor rock fracture changes, revealing the rock’s damage state and characterizing the damage evolution process during uniaxial cyclic loading and unloading. First, a damage variable equation was established based on AE and resistivity parameters, leading to the derivation of a corresponding damage constitutive equation. Uniaxial cyclic loading and unloading tests were then conducted on sandstone samples with varying water contents, continuously monitoring AE signals and resistivity, along with computed tomography scans before and after failure. The predictions from the damage constitutive equation were compared with experimental results. This comparison shows that the proposed damage variable equation effectively characterizes the damage evolution of sandstone during loading and unloading, and that the constitutive equation closely fits the experimental data. This study provides a theoretical basis for monitoring and assessing the responses of surrounding rock mass during underground excavation.</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

Damage evolution in sandstone under uniaxial cyclic loading and varying water contents: Theoretical and experimental investigation

  • Sheng Zhang,
  • Wei Bai,
  • Ding-ping Xu,
  • Hong Zheng,
  • Quan Jiang,
  • Zhi-wei Li

摘要

During underground excavation, the surrounding rock mass is subjected to complex cyclic stress, significantly impacting its long-term stability, especially under varying water content conditions where this effect is amplified. However, research on the mechanical response mechanisms of surrounding rock mass under such conditions remains inadequate. This study utilized acoustic emission (AE) and resistivity testing to monitor rock fracture changes, revealing the rock’s damage state and characterizing the damage evolution process during uniaxial cyclic loading and unloading. First, a damage variable equation was established based on AE and resistivity parameters, leading to the derivation of a corresponding damage constitutive equation. Uniaxial cyclic loading and unloading tests were then conducted on sandstone samples with varying water contents, continuously monitoring AE signals and resistivity, along with computed tomography scans before and after failure. The predictions from the damage constitutive equation were compared with experimental results. This comparison shows that the proposed damage variable equation effectively characterizes the damage evolution of sandstone during loading and unloading, and that the constitutive equation closely fits the experimental data. This study provides a theoretical basis for monitoring and assessing the responses of surrounding rock mass during underground excavation.