Slope stability against rainfall and preventive measures

• Main Authors: Rahardjo, Harianto, Satyanaga, Alfrendo, Leong, Eng Choon, Ng, Yew Song, Pang, Henry Tam Cheuk, Hua, Chai Juay
• Other Authors: School of Civil and Environmental Engineering
• Format: Conference or Workshop Item
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Civil engineering::Geotechnical
• Online Access: https://hdl.handle.net/10356/94069; http://hdl.handle.net/10220/7212
• Institution: Nanyang Technological University

Slope failures caused by rainfall are common occurrences in Singapore and Southeast Asia. Many residual soil slopes have a deep groundwater table with a thick unsaturated soil zone above the water table. Infiltration rate into slopes is governed by permeability of the unsaturated soil above the groundwater table. As a result, changes in negative pore-water pressure or soil suction and consequently in shear strength of unsaturated soil are a function of water content. NTU and HDB have embarked on research collaboration to study the mechanism of rainfall infiltration into residual soil slopes in Singapore under local climatic conditions and the effects of rainfalls on stability of slopes. Unsaturated soil mechanics and unsaturated soil properties are used in assessing stability of slopes against rainfall. Measurements of soil properties are carried out using unsaturated soil apparatuses and technology. In addition, preventive measures for rainfall-induced slope failures are investigated using the principles of unsaturated soil mechanics. Preliminary results of the assessment and preventive measures based on unsaturated soil mechanics principles are illustrated.