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http://dx.doi.org/10.9720/kseg.2015.2.299

Analysis on Failure Critical Depth of Unsaturated Landslide Zone According to the Geological Condition  

Nam, Koung-Hoon (Dept. of Earth and Environmental Sciences, Andong National University)
Kim, Min-Gyu (Dept. of Earth and Environmental Sciences, Andong National University)
Jeong, Gyo-Cheol (Dept. of Earth and Environmental Sciences, Andong National University)
Publication Information
The Journal of Engineering Geology / v.25, no.2, 2015 , pp. 299-304 More about this Journal
Abstract
Slope stability analysis of unsaturated soil slopes due to rainfall infiltration is an important issue in evaluating landslide analysis and stability assessment. The purpose of this study is to establish the critical depth considering weathered soil of parent rock and rainfall intensity at main scarp in national landslide. Based on the analytical results, it is found that as rainfall duration and Slope angle increased, the critical depth of gneiss-weathered soil increased from 3.00 m to 3.77 m, the critical depth of granite weathered-soil increased from 1.75 m to 2.40 m, and the critical depth of mudstone-weathered soil increased from 3.00 m to 4.15 m, respectively. The critical depth of granite-weathered soil with low cohesion and high internal friction angle is much lower than those of other soils. It is interestingly shown that a decrease in the safety factor is highly significant, much affected by the slope increase rather than the rainfall intensity.
Keywords
landslide; slope failure; critical depth; safety factor;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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1 van Genuchten, M. Th., 1980, A closed form equation for predicting hydraulic conductivity in unsaturated soils, Soil science society of America journal, 44(5), 892-898.   DOI
2 Bishop, A. W., 1955, The use of the slip circle in the stability analysis of slopes, Geotechnique, 5(1), 7-17.   DOI
3 Chae, B. G., Lee, S. H., Song, Y. S., Cho, Y. C., and Seo, Y. S., 2007, Characterization on the relationships among rainfall intensity, Slope angle and pore water pressure by a flume fest: in case of gneissic weathered soil, The Journal of Engineering Geology, 17(1), 57-64 (in Korean with English abstract).
4 Chae, B. G., Park, K. B., Park, H. J., Choi, J. H., and Kim, M. I., 2012, Analysis of slope stability considering the saturation depth ratio by rainfall infiltration in unsaturated soil, Journal of Engineering Geology, 22(3), 343-351 (in Korean with English abstract).   DOI
5 Collins, B. D. and Znidarcic, D., 2004, Stability analyses of rainfall induced landslides, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, New-York, 130(4), 362-372.   DOI
6 Fredlund, D. G. and Xing, A., 1994, Equations for the soil water characteristic curve, Canadian geotechnical journal, 31(4), 521-532.   DOI
7 Jung, S. S., Choi, J. Y., and Lee, J. H., 2009, Stability analysis of unsaturated weathered soil slope considering rainfall duration, Korean Society of Civil Engineers, 29(1), 1-9 (in Korean with English abstract).
8 Kim, J. H., 2002, Stability analysis on unsaturated weathered infinite slopes based on rainfall-induced wetting, MSc Thesis, Yonsei University, 1-90 (in Korean with English abstract).
9 Ng, C. W. W. and Shi, Q., 1998, A numerical investigation of the stability of unsaturated soil slopes subjected to transient seepage, Comput. Geotech., 22(1), 1-28.   DOI
10 Mein, R. G. and Larson, C. L., 1973, Modeling infiltration during a steady rain, Water Resource Research, 9(2), 384-394.   DOI
11 National Disaster Management Institute (NDMI), 2011, GIS-based stability analysis system of steep slope, Research report, National Institute of Disaster Prevention, 1-156 (in Korean).
12 National Disaster Management Institute (NDMI), 2012, GIS-based warning system for steep slope, Research report, National Institute of Disaster Prevention, 1-140 (in Korean).
13 Pradel, D. and Raad, G., 1993, Effect of permeability on the surficial stability of homogeneous slopes, Journal of Geotechnical Engineering and Geoenvironmental Engineering, 119(2), 315-332.   DOI
14 Rahardjo, H. and Lim, T. T., Chang, M. F., and Fredlund, D. G., 1995, Shear strength characteristics of a residual soil with suction, Canadian Geotechnical Journal, 32(1), 60-77.   DOI
15 Song, Y. S., 2013, Stability analysis of the unsaturated infinite slope considering suction stress under steady infiltration condition, Journal of the Korean geotechnical society, 29(9), 5-15 (in Korean with English abstract).   DOI