Authors: Song, Y-K; Oh, J-R; Jung, MS, Son, YJ

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Song, Y-K, Oh, J-R & Jung, MS, Son, YJ 2013, 'Risk evaluation of slope considering mechanical and hydraulic characteristics of unsaturated soils', in PM Dight (ed.), Slope Stability 2013: Proceedings of the 2013 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering, Australian Centre for Geomechanics, Perth, pp. 473-481,

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Rainfall is an important triggering mechanism of slope failure which accompanies severe damage and loss of life and property. Slope failure is mainly triggered by a deepening of the wetting band accompanied by a decrease in matric suction induced by water infiltration. Early warning methods for slope failure in Korea only tend to use rainfall intensity and duration as the main variables, not considering mechanical and hydraulic characteristics of unsaturated soils. In this study, geotechnical properties of unsaturated weathered soil, including basic physical properties, soil-water characteristics curve, unsaturated permeability curve, and unsaturated shear strength, were investigated in test beds in which slope failures frequently occurred. Also presented is a procedure for the risk evaluation of slope failures, which integrates the Factor of Safety of the infinite slope of unsaturated soil, considering not only rainfall intensity and duration, but also the mechanical and hydraulic properties of unsaturated soils.

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