Abstract

The shape of loess particles was determined from scanning electron microscope images and biaxial tests were simulated by the discrete element method. The effects of different percentages of angular, sub-angular, sub-rounded, rounded and well-rounded particles in the samples on the internal friction angle, coordination number and porosity of the loess are studied, and the evolution of the numerical simulation results during the tests are analysed from the microscopic level. The results show that when the combined roundness and combined ellipticity values decrease, that is, the irregular and flat particle percentage content decreases, the internal friction angle, the average coordination number between particles and the porosity of the sample decrease.

1. KEY POINTS

2. Scanning electron microscope images of loess are processed, and the percentage of particles with different shapes in each sample determined.

3. The microscopic and macroscopic changes of samples during biaxial compression are considered via the discrete element method.

4. The effects of different particle shape percentage combinations on the internal friction angle, coordination number and porosity of loess are investigated, and the experimental results are explained from the microscopic point of view.

摘要

通过扫描电子显微镜图像确定黄土颗粒的形状，并通过离散元方法模拟双轴试验。研究了样品中角状、亚角状、亚圆状、圆状和圆状颗粒的不同百分比对黄土内摩擦角、配位数和孔隙度的影响，以及数值模拟结果的演变过程。测试是从微观层面分析的。结果表明，当综合圆度和综合椭圆度值减小时，即不规则和扁平颗粒百分比含量降低时，样品的内摩擦角、颗粒间平均配位数和孔隙率降低。

1. 关键点

2. 对黄土的扫描电子显微镜图像进行处理，并确定每个样品中不同形状的颗粒的百分比。

3. 通过离散元方法考虑双轴压缩过程中样品的微观和宏观变化。

4. 研究了不同颗粒形状百分比组合对黄土内摩擦角、配位数和孔隙度的影响，并从微观角度解释了实验结果。