长江科学院院报 ›› 2024, Vol. 41 ›› Issue (9): 123-129.DOI: 10.11988/ckyyb.20230682

• 岩土工程 • 上一篇    下一篇

激光粒度仪在特殊土颗粒分析试验中的应用

丁国权(), 陈凯   

  1. 河海大学 岩土力学与堤坝工程教育部重点实验室,南京 210024
  • 收稿日期:2023-06-24 修回日期:2023-09-27 出版日期:2024-09-01 发布日期:2024-09-20
  • 作者简介:

    丁国权(1986-),男,安徽宣城人,实验师,硕士,主要从事非饱和土及堤坝工程等方面的研究。E-mail:

  • 基金资助:
    长江水科学研究联合基金重点支持项目(U2040221); 大学生创新训练项目(202210294049Z)

Application of Laser Particle Size Analyzer in Grain-size Analysis of Special Soils

DING Guo-quan(), CHEN Kai   

  1. Key Laboratory of Geomechanics and Embankment Engineering of Ministry of Education, Hohai University,Nanjing 210024, China
  • Received:2023-06-24 Revised:2023-09-27 Published:2024-09-01 Online:2024-09-20

摘要:

采用激光粒度仪对膨胀土、黄土和红土进行了颗粒分析试验,研究了取样质量和超声波分散时间对试验结果的影响,发现遮光率与取样质量呈现很好的线性正相关,给出了特殊土在激光粒度仪法试验中适宜的遮光率范围(15%~25%)、取样质量(膨胀土取0.1~0.2 g,黄土取0.4~0.8 g,红土取0.2~0.4 g)和超声波分散时间(膨胀土取6 min,黄土和红土取2 min);激光粒度仪法试验结果的离散性,对于黄土和膨胀土较小,但对红土相对较大,红土平行试验中粒组含量极差的最大值为10.1%;与密度计法相比,激光粒度仪法测得的胶粒(0,0.002]mm含量偏小,而黏粒(0.002,0.005]mm或更大粒组的含量则偏大,可能是因为两者试验原理的不同而导致的;2种方法对红土的测试结果差异较大,与红土的特殊性质有一定关系。研究成果为激光粒度仪在特殊土颗粒分析试验中的应用提供了借鉴。

关键词: 激光粒度仪, 特殊土, 颗粒分析, 密度计法, 遮光率

Abstract:

A laser particle size analyzer was employed to test the grain size of expansive soil, loess, and laterite to examine how sample mass and ultrasonic dispersion time affect the test results. A strong linear positive correlation was observed between shading rate and sample mass. Optimal conditions were determined for the laser particle size analyzer tests: shading rate between 15% and 25%, sample mass of 0.1-0.2 g for expansive soil, 0.4-0.8 g for loess, and 0.2-0.4 g for laterite, with ultrasonic dispersion times of 6 minutes for expansive soil and 2 minutes for loess and laterite. The test results are less discrete for loess and expansive soil but more discretized for laterite. In parallel tests, the maximum range in fraction content for laterite reached 10.1%. Compared to the densimeter method, the laser particle size analyzer reported lower contents of colloidal particles (smaller than 0.002 mm) and higher contents of clay particles (0.005-0.002 mm) or larger fractions. These discrepancies are likely due to the different principles underlying the two methods. The substantial differences in test results for laterite may be attributed to its unique properties. This study provides valuable insights for utilizing laser particle size analyzers in the grain-size analysis of special soils.

Key words: laser particle size analyzer, special soil, grain-size analysis, densimeter method, shading rate

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