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http://dx.doi.org/10.14481/jkges.2015.16.1.45

Case Study on the Instability of the Slopes in Unsaturated Residual Soils Considering the Rainfall Characteristics  

Nam, Samheon (Kunhwa Eng. Co. Ltd.)
Lee, Younghuy (Deptartment of Civil Engineering, Yeungnam University)
Oh, Seboong (Deptartment of Civil Engineering, Yeungnam University)
Publication Information
Journal of the Korean GEO-environmental Society / v.16, no.1, 2015 , pp. 45-53 More about this Journal
Abstract
This study has obtained Soil Water Retention Curve (SWRC) of the unsaturated soil from the volumetric pressure plate extractor test and the triaxial compression tests was also conducted. By using the rainfall data measured in the site the seepage analysis of unsteady flow was performed with the program of SEEP/W in Geostudio 2007 and stability of the slope was analyzed with SLOPE/W program. Results of analyses show that shear strength of the unsaturated soil increases with the increase of matric suction. And it was also found that the net volumetric stress and the apparent cohesion increased with the matric suction. The seepage analysis of rainfall represents that the increasing rate of negative pore pressure at the zone of large negative pore pressure is appeared to be high even though lower rainfall intensity, but this tendency declines with ground depth. The stability analysis of slope was carried out for the actual plane of failure with the data representing the field condition. The factor of safety thus calculated was about unity (1.0) or just below, which means that the adopted method of analysis is in good agreement with the field condition.
Keywords
Unsaturated soil; Matric suction; Suction stress; Seepage analysis of rainfall; Slope stability; Residual soil;
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