Effect of Antecedent Rainfall on Slope Failures in Tropical Mountainous Environmental Setting
Publication: Geo-Extreme 2021
ABSTRACT
Guam is a tropical region in the western Pacific that is characterized by mountainous terrain. It is often hit by storm events which bring heavy rainfall in short duration causing slope failures. In this research, soil samples were collected from mountainous slopes of the Piti-Asan watershed in central Guam and saturated as well as unsaturated soil properties including soil water retention curve test and unsaturated hydraulic conductivity functions were experimentally obtained. Transient seepage analysis was conducted on an idealized slope to obtain rainfall-induced changes in pore-water pressure profiles, and the output was coupled with slope stability analyses to study the effect of a recent storm event. Results show that unsaturated soil properties play a key role in estimating the accurate factor of safety of tropical hillslopes. In addition, studies show that there was a minimal effect of applied antecedent rainfall events on the stability of the hillslope.
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Geo-Extreme 2021
Pages: 11 - 20
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© 2021 American Society of Civil Engineers.
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Published online: Nov 4, 2021
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