Scholarlink

<p>The Paleogene red-bed mudstone in the northeastern Tibetan Plateau is highly susceptible to freeze–thaw cycling (FTC)-induced degradation, posing a significant threat to slope stability. However, the cross-scale mechanisms linking moisture content, micro-damage evolution, and macroscopic failure behavior remain insufficiently understood. This study systematically investigates the effects of FTC (0–12 cycles) under two water contents (ω = 10% and 15%), which were selected to represent typical unsaturated moisture increase scenarios caused by rainfall infiltration or rising groundwater levels, corresponding to 53.5% and 80.3% of the saturated water content, respectively. The main aim is to elucidate how varying moisture levels accelerate the cross-scale damage cascade from mineral alteration to structural degradation and eventual mechanical failure. Using integrated X-ray diffraction (XRD), scanning electron microscopy (SEM), computed tomography (CT), and uniaxial compression tests, the results indicate that elevated water content acts as a significant controlling factor throughout the degradation process. At the mineral scale, it intensifies lattice fatigue of expansive clay minerals (e.g., montmorillonite) and promotes dissolution of calcite cement. At the structural scale, higher moisture accelerates the transition of the pore system from an isolated configuration to a more connected and anisotropic network, as reflected by increased porosity, fractal dimension, coordination number, and fabric anisotropy. Mechanically, this enhanced micro-damage evolution is associated with a moisture-dependent nonlinear strength reduction (up to 68%) and an earlier transition from brittle to shear-dominated failure. Strong correlations (|r|&gt; 0.90) suggest that strength degradation is closely linked to increased pore complexity and connectivity. This study presents a material-specific, quantitative extension of existing multiscale freeze–thaw degradation frameworks, providing insights for predicting and assessing FTC-induced geohazards in cold-region red-bed strata.</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

A Moisture-Accelerated Cross-Scale Damage Cascade in Paleogene Red-Bed Mudstone Under Freeze–Thaw Cycling, NE Tibetan Plateau

  • 期刊论文

  • 发表日期：

    2026年7月24日

查看全文
  • Zihao Wang,
  • Zuopeng Wang,
  • Jianbing Peng,
  • Yunbing Chen,
  • Mingdong Zang,
  • Yiguo Xue,
  • Jianqi Zhuang

摘要

The Paleogene red-bed mudstone in the northeastern Tibetan Plateau is highly susceptible to freeze–thaw cycling (FTC)-induced degradation, posing a significant threat to slope stability. However, the cross-scale mechanisms linking moisture content, micro-damage evolution, and macroscopic failure behavior remain insufficiently understood. This study systematically investigates the effects of FTC (0–12 cycles) under two water contents (ω = 10% and 15%), which were selected to represent typical unsaturated moisture increase scenarios caused by rainfall infiltration or rising groundwater levels, corresponding to 53.5% and 80.3% of the saturated water content, respectively. The main aim is to elucidate how varying moisture levels accelerate the cross-scale damage cascade from mineral alteration to structural degradation and eventual mechanical failure. Using integrated X-ray diffraction (XRD), scanning electron microscopy (SEM), computed tomography (CT), and uniaxial compression tests, the results indicate that elevated water content acts as a significant controlling factor throughout the degradation process. At the mineral scale, it intensifies lattice fatigue of expansive clay minerals (e.g., montmorillonite) and promotes dissolution of calcite cement. At the structural scale, higher moisture accelerates the transition of the pore system from an isolated configuration to a more connected and anisotropic network, as reflected by increased porosity, fractal dimension, coordination number, and fabric anisotropy. Mechanically, this enhanced micro-damage evolution is associated with a moisture-dependent nonlinear strength reduction (up to 68%) and an earlier transition from brittle to shear-dominated failure. Strong correlations (|r|> 0.90) suggest that strength degradation is closely linked to increased pore complexity and connectivity. This study presents a material-specific, quantitative extension of existing multiscale freeze–thaw degradation frameworks, providing insights for predicting and assessing FTC-induced geohazards in cold-region red-bed strata.