Experimental investigation of the effect of interstitial liquid on the shear characteristics of geotechnical granular materials

Interstitial liquid between particles is a significant factor affecting the shear characteristics of geotechnical granular materials. To further investigate this issue, this study systematically conducted ring shear tests on quartz sand with different saturations and particle sizes. It was found that the impact of saturation on the shear characteristics of quartz sand has a strong correlation with particle size. The effective friction coefficient of coarse sand shows a trend of increasing and then decreasing with increasing saturation. The volume strain changes of quartz sand during shearing can be divided into three stages, with the trend in each stage significantly affected by saturation and particle size. The absolute crushing rate of coarse sand gradually decreases with increasing saturation. The smaller the particle size, the lower the likelihood of breakage. The findings provide scientific basis for further understanding the dynamic mechanisms behind the shear deformation and failure- induced disasters of geotechnical granular materials.