Abstract Subsea pipelines, trenching picks and ploughing blades are examples where soil-structure interaction occurs at very low vertical effective stress. Arches are multi-particle structures encountered during the interface shearing process, the existence of which dictates the properties of the overall granular assembly. In order to understand the behavior of dense granular materials in response to shearing under low confining pressure, physical modeling together with discrete element method (DEM) modeling of granular layers has been performed. Since friction can control the behaviors of granular flow, this study focuses on the effect of μ on the arch network as a parametric study. Grains have been subjected to horizontal shearing by a triangle wedge at an enlarged scale so that observations of the shearing process and behavior of particles can be made. The model was validated against physical modeling by comparing the rearrangement of selected particles, velocity vector field and arch network. During the shearing process, the arch network changed with the formation and collapse of arches, which was quantitatively analyzed in terms of arch size distribution and duration. The micromechanical responses from the granular assembly demonstrated that when μ increased, particle rearrangement shifted from sliding to rotation, resulting in longer and more durable arches. The investigation on contact forces showed that in-arch grains withstood larger forces and had a higher probability to participate in force chain than out-of-arch grains. Taking the effect of μ into consideration, the study explores the relationship among particle rearrangement, arch network, and force chains.

中文翻译：

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低约束条件下剪切过程中摩擦系数对拱网的影响

摘要 海底管道、挖沟镐和犁刀是在非常低的垂直有效应力下发生土壤-结构相互作用的例子。拱是在界面剪切过程中遇到的多颗粒结构，其存在决定了整个颗粒组件的特性。为了理解致密颗粒材料在低围压下响应剪切的行为，已经进行了颗粒层的物理建模和离散元方法 (DEM) 建模。由于摩擦可以控制颗粒流的行为，本研究重点研究 μ 对拱网络的影响作为参数研究。颗粒通过三角楔在放大的比例下受到水平剪切，以便可以观察剪切过程和颗粒的行为。通过比较选定粒子的重排、速度矢量场和拱形网络，该模型针对物理建模进行了验证。在剪切过程中，拱网络随着拱的形成和倒塌而发生变化，从拱尺寸分布和持续时间等方面进行定量分析。颗粒组件的微观力学响应表明，当 μ 增加时，颗粒重排从滑动转变为旋转，从而形成更长、更耐用的拱形。接触力研究表明，拱内晶粒比拱外晶粒承受更大的力，参与力链的概率更高。考虑到μ的影响，该研究探讨了粒子重排、拱形网络和力链之间的关系。