The discrete-element method (DEM) has gained popularity for developing a qualitative understanding of soil behaviour under a critical state soil mechanics (CSSM) framework. Most studies with a three-dimensional assembly of particles have used spheres as representative granular material to reduce computational demands. However, most granular materials – for example, sands – are not rounded, but possess features of angularity. Therefore, ellipsoid and cluster particles with different degrees of eccentricity were used in this study to evaluate the effect of the particle shape on the drained and undrained triaxial loading behaviour after isotropic and K₀ consolidation. The particle numerical properties and grain size distributions were kept the same for all specimens, irrespective of particle shape. The critical state data points for spheres and ellipsoids plotted on almost the same critical state line (CSL) in e–log(p′) space, whereas the CSLs of clusters plotted above them. Additionally, M lines shifted downward with increasing sphericity. It was also found that the stress ratio at the triggering of static liquefaction (η_IS = q/p′) in η_IS–ψ space was affected by particle shape and consolidation path. The dilatancy (d = dε_v^p/dε_q^p) was also affected by particle shape. It was found that dilatancy parameters for the SANISAND constitutive model are affected by particle shape, which may contribute to an improved understanding of particle shape in constitutive modelling.

中文翻译：

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颗粒形状如何影响临界状态、触发颗粒材料的不稳定和膨胀——来自 DEM 研究的结果

离散元方法 (DEM) 在临界状态土壤力学 (CSSM) 框架下开发对土壤行为的定性理解而广受欢迎。大多数对粒子的三维组装的研究都使用球体作为代表性的颗粒材料，以减少计算需求。但是，大多数粒状材料（例如沙子）不是圆形的，而是具有棱角的特征。因此，本研究使用不同偏心度的椭球和簇状颗粒来评估颗粒形状对各向同性和K ₀后排水和不排水三轴加载行为的影响。合并。无论颗粒形状如何，所有样品的颗粒数值特性和粒度分布都保持相同。球体和椭球体的临界状态数据点绘制在e –log( p ') 空间中几乎相同的临界状态线 (CSL) 上，而簇的CSL绘制在它们上方。此外，M线随着球形度的增加而向下移动。还发现η _IS – ψ空间中静态液化触发时的应力比 ( η _IS  =  q / p ' )受颗粒形状和固结路径的影响。剪胀度 ( d  = dε _v ^p /d ε _q ^p ) 也受颗粒形状的影响。发现 SANISAND 本构模型的剪胀参数受颗粒形状的影响，这可能有助于更好地理解本构模型中的颗粒形状。