基于 DEM 的颗粒级配对粗颗粒土三轴试验影响分析

通过建立DEM离散元模型，分析不同颗粒组成的土颗粒三轴试验中的应力应变及强度特性。为充分描绘不同颗粒级配对应力应变特性的影响，在采用传统应力应变曲线基础上，对颗粒三轴试验中颗粒位移场的变化进行了分析。结果表明，随着围压的增加，颗粒位移场变得均匀，粗粒土更容易发生体缩变形，向更密实的挤压状态转变，强度增高。曲率系数与不均匀系数对土的强度及变形性能影响较大，在级配曲线连续的条件下，有效粒径与中值粒径或限制粒径相差较大时，粗骨料之间接触形成骨架结构，其内摩擦角增大，强度及抗变形性能提高。

Analysis of influence of particle gradation on triaxial test of coarse-grained soil based on DEM

By establishing a DEM discrete element model, the stress-strain and strength characteristics of soil particles composed of different gradations in the triaxial test are analyzed. In order to fully describe the influence of different particle gradations on the stress-strain characteristics, this study adopts the traditional stress-strain curve. On this basis, an analysis of the changes of the particle displacement field in the particle triaxial test is carried out. The results show that with the increase of the confining pressure, the particle displacement field becomes uniform, the coarse-grained soil is more prone to shrinkage and deformation, transforming to a more densely compressed state, and its strength increases. Curvature coefficient and non-uniformity coefficient have a great influence on the strength and deformation performance of soil. Under the condition of continuous gradation curve, when the effective particle size and the median particle size or the limit particle size are greatly different, the coarse aggregates contact each other. A skeleton structure is formed, the internal friction angle is increased, and the strength and anti-deformation performance are improved.