Analysis of Residual Shear Strength Characteristics for Fine Content Using Ring Shear Test Apparatus

In Korea, the frequency of landslides and debris flow increases because of the concentration of rainfall in summer, which results in increased damage. Therefore, the shear characteristics of granite-weathered soil, including fine particles, were investigated using a ring shear test apparatus to evaluate the flowability of debris. For a reliable shear stress measurement, the shear rate was set by conducting a test with varying shear rates. The shear stress increased as the fine content increased at low normal stress, and softening behavior was clearly visible. However, as the normal stress increased, the hardening behavior changed, and the shear stress increased as the fine content decreased. In addition, as the fine content increased, the internal friction angle, which is the peak and residual stress coefficient, decreased, and the cohesion tended to increase.