【摘要】 高速公路的碎石基层性能受碎石颗粒的性质影响，颗粒的形状是影响碎石基层压载性能的一个重要特征，用角度指标和球度指标来表示。通过离散元模拟采用重叠刚性簇方法研究了颗粒角度和颗粒球度对碎石土宏观和微观力学特性的影响。建立了相同孔隙比条件下不同颗粒形状的碎石土三轴试验数值模型，探讨了内摩擦角、体应变、力学配位数、组构及接触力链的演化。结果表明：内摩擦角随角度AI的增大而增大，随球度SPH的增大而减小；大应变下的剪胀率随着AI的增加而显著增加，剪胀率随球度SPH的增加而先增大后减小；微观方面，力学配位数随角度AI的增大而增大，随球度SPH的增大而减小；接触偏组构随着AI的增加和SPH的降低而增加；颗粒形状影响微观接触力链的分布进而影响试样宏观抗剪强度。更多还原

【Abstract】 The performance of gravel layer in highways is influenced by the properties of the gravel particles. The particle shape is a key characteristic affecting the bearing capacity of the gravel layer, represented by angularity and sphericity indices.The impact of particle angularity and sphericity on the macroscopic and microscopic mechanical properties of gravel soil was investigated through discrete element simulation employing the overlapping rigid clusters method. Numerical models of triaxial tests for gravel soil with different particle shapes under the same porosity conditions were established, and the evolution of internal friction angle, volumetric strain, mechanical coordination number, structure, and contact force chain was explored. The results indicate that the internal friction angle increases with the increase of angularity index( AI) and decreases with the increase of sphericity index(SPH). Under large strains, the shear dilation ratio significantly increases with increasing AI, while it initially increases and then decreases with the increase of SPH. On a microscopic scale, the mechanical coordination number increases with AI and decreases with SPH. The deviatoric fabric increase with the increase of AI and the decrease with SPH.Particle shape influences the distribution of microscopic contact force chains, thereby affecting the macroscopic shear strength.更多还原