Particle morphology, including particle shape and particle size, has significant influence on the shear behavior of granular soils. The effect of particle shape has been investigated in several studies. However, the effect of particle size has not yet been paid much attention. In this study, the effect of particle size on the shear strength and the stress–dilatancy behavior of sands was assessed through a series of drained triaxial compression tests on dense uniform silica sands. The effect of particle size was analyzed on various aspects of mechanical behavior: the stress–strain response, the shear band formation, the peak-stress axial strain, the peak dilation angle, the peak friction angle, the critical-state friction angle, and the stress–dilatancy relations. Furthermore, we noticed that the particle shape of silica sands usually varies with particle size. The effect of this morphologic characteristic on mechanical behavior was also discussed by comparing the experimental results on silica sands with those reported on glass beads and Péribonka sand (Harehdasht et al. in Int J Geomech 17:04017077, 2017). The results show that particle size significantly influences the peak friction angle, the peak dilation angle and the stress–dilatancy behavior. The underlying mechanism for the effect of particle size was discussed from the perspective of kinematic movement at particle level.

颗粒形态，包括颗粒形状和粒径，对颗粒状土壤的剪切行为具有重要影响。在一些研究中已经研究了颗粒形状的影响。但是，粒径的影响尚未引起足够的重视。在这项研究中，通过在致密的均匀硅砂上进行的一系列排水三轴压缩试验，评估了粒径对砂的剪切强度和应力-剪胀行为的影响。在机械行为的各个方面分析了粒径的影响：应力-应变响应，剪切带形成，峰值应力轴向应变，峰值膨胀角，峰值摩擦角，临界摩擦角和应力-剪胀关系。此外，我们注意到硅砂的颗粒形状通常随颗粒大小而变化。通过将硅砂上的实验结果与玻璃珠和Péribonka砂上报道的结果进行比较，还讨论了这种形态特征对机械行为的影响（Harehdasht等人在Int J Geomech 17：04017077，2017）。结果表明，粒径显着影响峰摩擦角，峰扩张角和应力-剪胀行为。从颗粒级运动学的角度讨论了影响颗粒尺寸的潜在机理。Int J Geomech 17：04017077，2017）。结果表明，粒径显着影响峰摩擦角，峰扩张角和应力-剪胀行为。从颗粒级运动学的角度讨论了影响颗粒尺寸的潜在机理。Int J Geomech 17：04017077，2017）。结果表明，粒径显着影响峰摩擦角，峰扩张角和应力-剪胀行为。从颗粒级运动学的角度讨论了影响颗粒尺寸的潜在机理。