A CFD–DEM study on the suffusion and shear behaviors of gap-graded soils under stress anisotropy
A CFD–DEM study on the suffusion and shear behaviors of gap-graded soils under stress anisotropy
复制标题
DOI：
10.1007/s11440-022-01755-7
复制
发表时间：
2022-12
期刊：
影响因子：
5.7
通讯作者：
Z. Hu;J. Z. Li;Y. D. Zhang;Z. X. Yang;J. K. Liu
中科院分区：
文献类型：
--
作者：
Z. Hu;J. Z. Li;Y. D. Zhang;Z. X. Yang;J. K. Liu
本研究研究了各向异性应力条件下间隙级配土的漫射和力学行为的演变。使用耦合计算流体动力学和离散元方法 (CFD-DEM) 对颗粒聚集体和渗流之间的相互作用进行建模。进行了一系列的扩散试验，然后进行排水三轴压缩和拉伸试验，以探讨应力各向异性对扩散的引发和发展以及侵蚀样本的剪切响应的影响。结果表明，主要有效应力与主要流动方向一致的样本更容易被侵蚀，这可以通过更严重的细粉损失、体积收缩和孔隙比变化来证明。在三轴压缩和拉伸条件下，弥漫往往会降低试样的峰值强度、峰值摩擦角和割线刚度，而其对临界状态剪切强度的影响可以忽略不计。在扩散和剪切阶段，通过各种配位数测量来跟踪接触网络效率的变化。通过强和弱法向接触力的方向分布来评估扩散和剪切过程中应力各向异性的演变。
This study investigates the evolution of suffusion and mechanical behaviors of gap-graded soils under anisotropic stress conditions. The interactions between granular assembly and seepage flow are modeled using the coupled computational fluid dynamic and discrete element method (CFD–DEM). A series of suffusion tests followed by drained triaxial compression and extension tests are performed to explore the influence of stress anisotropy on the initiation and development of suffusion and the shear responses of eroded specimens. The results reveal that the specimens with the major principal effective stress aligned with the primary flow direction are more erodible evidenced by more severe fines loss, volumetric contraction, and void ratio changes. Suffusion tends to reduce the peak strength, peak friction angles, and secant stiffness of specimens under both triaxial compression and extension conditions, while its impact on the critical-state shear strength is negligible. The change of contact network efficiency is tracked by various coordination number measures during the suffusion and shear stages. The evolution of stress anisotropy during suffusion and shearing is evaluated by the directional distributions of the strong and weak normal contact forces.