Effects of temperature, pore fluid composition and rate of shearing on the residual shear strength of soils
Effects of temperature, pore fluid composition and rate of shearing on the residual shear strength of soils
The residual shear strength is a crucial parameter in the post-failure behaviour of landslides. Many studies have shown that this parameter depends on the rate of shearing according to the normal stress and soil composition. Some researchers have shown that the composition of the pore fluid, which in landslide shear zones is typically an aqueous solution containing various dissolved ions, also can affect the residual shear strength. Smectites, in particular, can exhibit dramatic strengthening upon exposure to a concentrated salt solution. Few researchers have begun to evaluate the residual shear strength while also controlling the temperature during testing. Results demonstrated both strengthening and weakening upon heating, depending on soil composition. Owing to the coupled nature of hydraulic, thermal, chemical, and mechanical processes in soil, coupled effects also are expected; however, these effects are largely unexplored. We performed ring-shear experiments on pure clays and natural soils to obtain some insight into these coupled effects. We observed, for instance, that the effect of temperature fades away as the rate of shearing increases or the clay fraction decreases. We also observed some relationship between the shear rate effect and pore fluid composition. Understanding coupled processes in soils remains challenging; however, experiments may help improve our understanding of field-scale events, such as landslide reactivation and runout upon complex changes in boundary conditions.
Gianvito Scaringi; O. P. Dhakal; Marco Loche
18th European Conference on Soil Mechanics and Geotechnical Engineering (ECSMGE2024)
B - Geohazards
Contact Information
- Secretary General - Dr A M McNamara
- Email: [email protected]
- Phone: +44 20 7040 8154
- City, University of London
- Northampton Square
- London EC1V 0HB. United Kingdom