Scholarlink

<p>This study explores the uniaxial compression mechanical behaviors and fracture evolution of tight sandstone after high-temperature treatment (25&#xa0;°C-800 °C). The results show that high temperature induces irreversible changes in rock physical properties, including regular color transition, continuous mass/density loss and <i>P</i>-wave velocity deterioration, and 600&#xa0;°C is identified as the critical temperature for severe structural damage. Mechanical parameters including compressive strength, peak strain and elastic modulus present a three-stage evolution of enhancement (25&#xa0;°C-400°C), degradation (400&#xa0;°C-600°C) and partial recovery (600&#xa0;°C-800°C), controlled by water evaporation, mineral transformation and thermal cracking. With the increase of temperature, tensile-dominated fracture gradually transforms into tensile-shear mixed failure, accompanied by rising spalling area and fracture complexity. Fractal analysis indicates 400&#xa0;°C is the threshold of maximum fragmentation degree and energy dissipation. Multi-index acoustic emission results reveal non-monotonic variations of cumulative energy and <i>b</i>-value, and the correlation dimension reflects the transition from disordered microcracking to ordered macro-fracture propagation. RA-AF analysis verifies the increased proportion of shear cracks under high temperature. Microscopic tests demonstrate that quartz phase transition, clay decomposition and differential thermal expansion dominate the macroscopic thermal response. This study defines 400&#xa0;°C and 600&#xa0;°C as two key critical temperatures, and provides theoretical support for the stability evaluation of deep high-temperature engineering such as geothermal exploitation and nuclear waste disposal.</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

Experimental study on uniaxial compression mechanical properties and fracture fractal characteristics of dense sandstone under different temperature conditions

  • 期刊论文

  • 发表日期：

    2026年7月6日

查看全文
  • Wang Hongjian,
  • Sun Qihan,
  • Zhao Shankun,
  • Zhang Wenchang,
  • Zhao Fei,
  • Liu Guilin,
  • Yin Bohao,
  • Li Yuzhi

摘要

This study explores the uniaxial compression mechanical behaviors and fracture evolution of tight sandstone after high-temperature treatment (25 °C-800 °C). The results show that high temperature induces irreversible changes in rock physical properties, including regular color transition, continuous mass/density loss and P-wave velocity deterioration, and 600 °C is identified as the critical temperature for severe structural damage. Mechanical parameters including compressive strength, peak strain and elastic modulus present a three-stage evolution of enhancement (25 °C-400°C), degradation (400 °C-600°C) and partial recovery (600 °C-800°C), controlled by water evaporation, mineral transformation and thermal cracking. With the increase of temperature, tensile-dominated fracture gradually transforms into tensile-shear mixed failure, accompanied by rising spalling area and fracture complexity. Fractal analysis indicates 400 °C is the threshold of maximum fragmentation degree and energy dissipation. Multi-index acoustic emission results reveal non-monotonic variations of cumulative energy and b-value, and the correlation dimension reflects the transition from disordered microcracking to ordered macro-fracture propagation. RA-AF analysis verifies the increased proportion of shear cracks under high temperature. Microscopic tests demonstrate that quartz phase transition, clay decomposition and differential thermal expansion dominate the macroscopic thermal response. This study defines 400 °C and 600 °C as two key critical temperatures, and provides theoretical support for the stability evaluation of deep high-temperature engineering such as geothermal exploitation and nuclear waste disposal.