Effect of Pore Water Salinity on the Residual Strength of Kaolinite
Mohammadreza Jebeli, Siamak Yoosefi, William J. Baker, Christopher L. Meehan
Abstract
Sea level rise and seawater intrusion induced by climate change increase soil pore water salinity in coastal regions. This can affect soil compressibility and shear strength, especially for fine-grained soils. One of the main parameters to characterize the shear strength of soils is residual shear strength, which is essential for analyzing the stability of active landslides. In the US, this parameter is typically measured using a Bromhead ring shear device. However, soil extrusion during tests using this device causes wall friction, leading to the overestimation of shear strength. To address this issue, two Bromhead ring shear devices with modified beveled top platens were tested. Results showed that the beveled platen significantly reduced wall friction, providing more accurate residual shear strength measurements. This study also investigated the effect of pore water salinity increase on the kaolinite’s residual strength. The results showed that an increase in salinity from freshwater to seawater levels did not substantially affect the kaolinite’s residual shear strength.