Deriving Sensitivity and Rapidity from the Clay Cutter Test: An Assessment of Remoulding Capacity and Rapidity Param eter Development

Abstract

Landslides are among the most destructive natural hazards affecting Sweden and other Nordic countries, which makes their prevention an important geotechnical challenge. In Sweden, landslide risk assessments commonly involve laboratory and in situ investigations of soil conditions, where soil sensitivity is often estimated using the fall cone test (FC). However, this method is associated with known limitations, and the resulting parameters require empirical correction factors. This has motivated the development of alternative approaches for characterizing sensitive clays, which may also provide insight into the rate of strength degradation during disturbance. The Clay Cutter Test (CCT) is a recently developed laboratory device intended for measuring the undrained shear strength of clay and is currently undergoing further development and evaluation. This study explores the potential of the CCT for estimating remoulded shear strength, sensitivity and rapidity and compares its behaviour with that of the conventional FC test, using previously obtained data for validation. The results suggest that full remoulding, needed for assessing sensitivity, is not consistently achieved within the tested CCT procedures. However, the obtained results appear to align best with more homogeneous clay conditions, similar to those for which the FC test is developed. Due to the lack of full remoulding for several soil samples, the rapidity analysis was only performed on homogeneous clay samples. The results indicated that there are promising results, however because of the uncertainty in the remoulding process and shortage of clay test samples, a sufficient conclusion could not be drawn. This suggests that further investigation of the remoulding behaviour using the CCT is needed to better understand its potential use.