Experimental Study on Micro-macro Shear Properties of Sand Considering Particle Size

In order to explore the influence of sand particle size on its shear resistance, strain controlled direct shear apparatus and discrete element software were used to conduct shear tests on three kinds of sand with different average particle sizes, and the shear characteristics of sand were analyzed from both macro and micro perspectives. The results show that the shear strength increases with the increase of normal stress and average particle size, and the internal friction angle increases with the increase of average particle size. A multivariate linear prediction model of sand shear strength is established, and the model prediction is accurate. The thickness of shear band increases with the increase of average particle size. The relationship between shear band thickness and normal stress can be expressed by a quadratic function. Therefore, in the actual project construction, reasonable use of sand with larger particle size is conducive to improving the shear capacity.