土工基础

土工基础 ›› 2025, Vol. 39 ›› Issue (3): 500-506.

• 测试技术 • 上一篇    

赤水红层残积土物理特性及孔隙特征研究

杨 涛1,杨根兰1,2,3,李赛东1   

  1. （1.贵州大学资源与环境工程学院，贵阳 550025；2.贵州大学喀斯特地质资源与环境教育部重点实验室，贵阳 550025；3.贵州省山地地质灾害防治工程技术研究中心，贵阳 550025）
  • 收稿日期:2025-02-26 修回日期:2025-03-19 出版日期:2025-06-30 发布日期:2025-08-05
  • 通讯作者: 杨根兰（1977-），女，博士，副教授，研究方向为岩体稳定及环境工程地质。
  • 作者简介:杨涛（2000-），男，硕士研究生，研究方向为红层地质灾害。
  • 基金资助:
    国家自然科学基金（42067046）；贵州省科技成果转化联合基金项目（黔科合成果-LH2024-重大025）；贵阳市科技规划项目（筑科合同［2023］13-10）；2025年贵州省基础研究计划（自然科学）重点项目（黔科合基础ZD［2025］007）

Microstructural Evolution and Physicomechanical Behavior of Lateritic Residual Soils in Guizhou Red Beds: A Multiscale Investigation from the Chishui Area

YANG Tao1, YANG Genlan1,2,3， LI Saidong1   

  1. (1.College of Resource and Environment Engineering, Guizhou University, Guiyang 550025；
    2.Key Laboratory of Karst Geology Resources and Environment, Ministry of Education, Guizhou University, Guiyang 550025；
    3.Guizhou Provincial Mountain Geological Disaster Prevention and Control Engineering Technology Research Center, Guiyang, 550025)
  • Received:2025-02-26 Revised:2025-03-19 Online:2025-06-30 Published:2025-08-05

摘要： 红层残积土作为红层浅层大密集灾变孕育的物质基础，其物理特性及孔隙特征对红层土坡的水份入渗与运移起到核心作用，为研究其物理特性及其在竖向上的孔隙特征。以不同取样深度的红层残积原状土样为试验对象，通过X射线衍射试验、电子显微镜扫描试验（SEM）获得土体矿物成分及微观结构，在此基础上进行常规了物理特性试验，最后通过压汞试验获得该土的孔隙特征。结果表明：①赤水红层残积土的矿物成分主要有石英、粘土、钾长石和赤铁矿，随着深度增加，粘土含量增加，石英含量减少。②随着深度增加，红层残积土的天然含水率上升，密度逐渐增大，颗粒尺寸差异较小，级配良好。③土体的孔隙率随深度增加逐渐降低，特征曲线具有相似性，并且曲线的趋势均显示出明显的分界点；综合分形结果和前人的研究提出了适合红层残积土孔隙类型划分界限孔径值：小于0.05 μm的孔隙为颗粒内孔隙，0.05~0.35 μm的孔隙为微孔，0.35~3.5 μm的孔隙为小孔，3.5~25 μm的孔隙为中孔，大于25 μm的孔隙为大孔。


关键词: 红层残积土, 矿物成分, 压汞试验, 物理性质, 界限孔径

Abstract: The residual soil in the red bed constitutes a fundamental material basis for the development of large-scale density-related hazards in its shallow deposits. The physical properties and pore characteristics of this soil are essential for understanding the infiltration and movement of the water within red bed soil slopes to study its physical properties and its vertical porosity characteristics. This study investigates the undisturbed residual soil samples collected at various depths. The mineral composition and microstructure of the soil are examined using the X-ray diffraction (XRD) and the scanning electron microscopy (SEM). Based on these analyses, conventional physical property tests are performed, and the pore characteristics of the soil are subsequently evaluated using the mercury intrusion porosimetry. The findings of this study demonstrate that: (1) The mineral composition of the residual soil in the Chishui Red Beds primarily consists of quartz, clay, potassium feldspar, and hematite. With the increasing of sampling depth, the clay content increases, while the quartz content decreases. (2) As the sampling depth increases, the natural moisture content of the residual soil in the red bed rises, leading to a gradual increase in density. The particle size variation is minimal, and the soil exhibits good gradation. (3) The porosity of the soil gradually decreases with increasing depth. The characteristic curves exhibit similarity, and the trend of the curves clearly shows a distinct boundary point. Based on the comprehensive fractal results and previous research, a suitable boundary pore size value for classifying the pore types of the red bed residual soil is proposed: pores smaller than 0.05 μm are classified as the intragranular pores; those between 0.05 and 0.35 μm are classified as the micropores; pores ranging from 0.35 to 3.5 μm are identified as the small pores; those from 3.5 to 25 μm are classified as the medium pores; and pores larger than 25 μm are categorized as the large pores. 

Key words: Red Bed Residual Soils, Mineral Component, Mercury Injection Test, Physical Property, Boundary Pore Size

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