Shear Strength of Aeolian Sand Sediments

Abstract

Abstract. The anti-erodibility of aeolian sand sediments represents their resistance to airflow shear and is closely associated with soil shear strength. However, there have been few studies on the anti-erodibility of sediments from the perspective of shear strength. In this study, we performed shear strength experiments for four categories of sediments at different values of normal stress. All samples were oven-dried prior to the shear tests. The main conclusions were as follows. The shear strength of sediments increased linearly with normal stress and grain diameter. Organic matter may weaken the shear strength. The impact of bulk density and CaCO3 content on the shear strength did not follow consistent rules, but RCaCO3/RBulk (where RCaCO3 is the ratio of CaCO3 content between two samples, and RBulk is the difference in bulk density) determines the relative contribution of each factor to shear strength. The cohesion, internal friction angle, and shear strength increased with increasing grain diameter. They also increased with increasing sorting coefficient when the sorting coefficient was greater than 0.6, while the opposite trend occurred with sorting coefficients less than 0.6. There was a positive linear correlation between cohesion and threshold friction velocity (R2 = 0.91). This study improves our understanding of shear strength, providing basic data with which to construct a dynamic model of aeolian sand transport by wind action. Keywords: Bulk density, Cohesion, Grain diameter, Internal friction angle, Shear strength, Sorting coefficient, Threshold friction velocity.