Abstract This study presents the effects of the particle shape on soil arching by simulating the trapdoor problem using the discrete element method (DEM). A new method for preparing the samples with irregular particle in the DEM is proposed to obtain a similar and reasonable initial stress state. Simple monitoring of the strain field is demonstrated. The results indicate that as the trapdoor moves downward, the critical height at which the measurable differential settlement vanishes increases then remains steady. The final critical height increases with decreasing sphericity or increasing roundness, in which the sphericity is the main influencing factor. Two types of shear bands propagate from the edge of the trapdoor into the specimens. As the interlocking between the irregular particles increases, the shear strain decreases, but the dilation increases inside the shear band. The particle shape affects the development rate of soil arching, but has a limited effect on the ultimate soil arching behaviour. The rotation of the major principal directions of anisotropy and the decrease in the anisotropy intensity are microcosmic reason of soil arching. Both of the rotation and decrease mainly occur in a relatively small trapdoor displacement, restricted by the increase in the interlocking between irregular particles.

中文翻译：

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颗粒形状对二维土拱形成的影响

摘要 本研究通过使用离散元方法 (DEM) 模拟陷门问题，展示了颗粒形状对土拱的影响。提出了一种在DEM中制备具有不规则颗粒样品的新方法，以获得相似且合理的初始应力状态。演示了对应变场的简单监测。结果表明，随着活板门向下移动，可测量差异沉降消失的临界高度增加然后保持稳定。最终临界高度随着球度的减小或圆度的增大而增大，其中球度是主要影响因素。两种类型的剪切带从活板门的边缘传播到标本中。随着不规则颗粒之间的互锁增加，剪切应变减小，但在剪切带内膨胀会增加。颗粒形状影响土拱的发展速度，但对最终土拱行为的影响有限。各向异性主方向的旋转和各向异性强度的降低是土拱形成的微观原因。旋转和下降都主要发生在相对较小的活板门位移中，受不规则粒子之间互锁增加的限制。