Characteristic of Erosion Properties and Relationship With Geotechnical Properties for Red Riverbank Soil in Hanoi, Vietnam

Abstract

Soil erosion properties are the main factors affecting riverbank and river channel stability. In this paper, a modified water flume in the laboratory was conducted to evaluate the characteristic of erosion properties including the critical shear stress, the slope of the erosion curve, and erosion rate. The relationships between erosion properties and geotechnical properties as dry density, grain size distribution, shear strength, and soil suction were built. Results obtained from laboratory tests indicate (i) the clay content, cohesion force, residual suction has a great effect and linear correlation in the relationships with the critical shear stress and erosion rate. While the change in clay content leads to a markedly change in the erosion rate. The difference of 5 % clay content enough to build great effects on the erosion rate curve for the Silt soil group; (ii) the sand content has the greatest influence on the slope of the erosion curve (the initial slope and the erosion slope); (iii) the density also has a close relationship with the critical shear stress and the erosion slope, but not for a fine–sand mixture with clay content less than 10%. Based on obtained results and relationships found in this paper, the cohesion force and residual suction should be considered in process of soil riverbank improvement and riverbank undercutting erosion protections.