Suction profiles of residual soil slopes

• Main Author: Ho, Jeffrey Jun Hua
• Other Authors: Leong Eng Choon
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Civil engineering
• Online Access: http://hdl.handle.net/10356/78292
• Institution: Nanyang Technological University

Two-thirds of Singapore geology consists of residual soil. Unsaturated residual soil slopes are subject to failure with increasing rainfall as the soil loses suction on saturation. Therefore, the main objective of this project was to determine the typical suction profiles of a residual soil slope to evaluate its factor of safety for the various suction profiles. Matric suction was measured using “Quick Draw” tensiometers in the field and weather data from the nearest weather station was collected. The measurement and weather data were then analyzed to produce pore-water pressure profiles for wet and dry days which allowed the estimation of the factor of safety of the slope. The residual soil slope was found to be safe regardless of changes in pore-water pressure profile, and the most effective monitoring scheme for the residual soil slope was found to be based on a 3-day normalized antecedent rainfall. The results gave a better understanding of how residual soil slopes can be monitored for practical assessment of slope stability.