Scholarlink

<p>Investigating the durability of containment materials under varying environmental temperatures and their long-term mechanical and hydraulic characteristics is key to ensuring reliability and sustainability in underground engineering applications. This study conducted experiments on granite samples subjected to high-temperature heating (ranging from 25 to 400&#xa0;°C) and liquid nitrogen (LN<sub>2</sub>) cooling. Using uniaxial compression and Brazilian tests, we systematically analyzed the physical and mechanical properties of the treated granite, including tensile and compressive strength, acoustic emission characteristics (ring counts, peak frequency, RA-AF), and the evolution of fracture morphology. Additionally, three-dimensional laser scanning technology was employed to further characterize the fracture surfaces, and the degree of damage inflicted by thermal shock was quantified using the brittleness index and damage variables. Experimental results indicate that heating–LN<sub>2</sub> cooling cycles significantly alter the mechanical properties and failure modes of granite, with elevated temperatures markedly promoting crack propagation and structural degradation. Crack width increases exponentially with temperature, and acoustic emission parameters also rise significantly with temperature, indicating intensified microcrack expansion and fracturing within the rock. As the temperature increases, thermal stress accumulates inside the rock, causing microcracks to gradually expand and evolve into transgranular fractures, transitioning from tensile failure to a more complex rupture mode. Additionally, uniaxial compression and Brazilian tests reveal that both compressive and tensile strengths of the samples decrease substantially with increasing temperature, and the loading method significantly affects the fracture characteristics. Three-dimensional fracture surface scanning analysis shows that heating and cooling treatments increase the surface and fracture surface roughness of the rock, with a concurrent rise in crack morphology complexity. Analysis based on a damage mechanics model demonstrates that high-temperature and LN<sub>2</sub> cooling cycles accelerate the disordered expansion of internal microcracks, leading to more complex rock deformation and damage evolution. The coupled damage model exhibits higher predictive accuracy across different temperature ranges.</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

Effects of heating–cooling on the mechanical properties and damage evolution of granite for underground cryogenic storage

  • 期刊论文

  • 发表日期：

    2026年4月18日

查看全文
  • Yi Xue,
  • Linchao Wang,
  • Yuhe Cai,
  • Jia Liu,
  • P. G. Ranjith,
  • Feng Gao,
  • Heping Xie,
  • Yong Liu

摘要

Investigating the durability of containment materials under varying environmental temperatures and their long-term mechanical and hydraulic characteristics is key to ensuring reliability and sustainability in underground engineering applications. This study conducted experiments on granite samples subjected to high-temperature heating (ranging from 25 to 400 °C) and liquid nitrogen (LN2) cooling. Using uniaxial compression and Brazilian tests, we systematically analyzed the physical and mechanical properties of the treated granite, including tensile and compressive strength, acoustic emission characteristics (ring counts, peak frequency, RA-AF), and the evolution of fracture morphology. Additionally, three-dimensional laser scanning technology was employed to further characterize the fracture surfaces, and the degree of damage inflicted by thermal shock was quantified using the brittleness index and damage variables. Experimental results indicate that heating–LN2 cooling cycles significantly alter the mechanical properties and failure modes of granite, with elevated temperatures markedly promoting crack propagation and structural degradation. Crack width increases exponentially with temperature, and acoustic emission parameters also rise significantly with temperature, indicating intensified microcrack expansion and fracturing within the rock. As the temperature increases, thermal stress accumulates inside the rock, causing microcracks to gradually expand and evolve into transgranular fractures, transitioning from tensile failure to a more complex rupture mode. Additionally, uniaxial compression and Brazilian tests reveal that both compressive and tensile strengths of the samples decrease substantially with increasing temperature, and the loading method significantly affects the fracture characteristics. Three-dimensional fracture surface scanning analysis shows that heating and cooling treatments increase the surface and fracture surface roughness of the rock, with a concurrent rise in crack morphology complexity. Analysis based on a damage mechanics model demonstrates that high-temperature and LN2 cooling cycles accelerate the disordered expansion of internal microcracks, leading to more complex rock deformation and damage evolution. The coupled damage model exhibits higher predictive accuracy across different temperature ranges.