Estimation of Change in Slope Stability Due to Rainfall Varied with Time, Based on Unsaturated Soil Mechanics
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Recently, slope failure due to rainfall occurs frequently and inflicts serious damage. However, slope characteristics that reflect stability, such as gradient, length, thickness of weathered layer, and groundwater condition, differ from one slope to another. Because of this, it is difficult to estimate the risk of slope failure using a single uniform standard. A simple way to model a slope and estimate risk according to rainfall pattern is needed. In this study, a way to estimate slope stability in the framework of unsaturated soil mechanics is proposed. Here, the surface failure of a long slope covered with weathered soil is the target. Various slope gradients and rainfall intensities are considered as influential factors on slope stability. First, rainfall infiltration is simulated with soil/water/air coupled finite element analysis code, DACSARMP. Next, the factor of safety is calculated using the distributions of pore-water pressure and soil moisture obtained from seepage analysis.
Keywordsslope stability rainfall seepage analysis
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- Ishihara, Y. and S. Kobatake (1979): Runoff Model for Flood Forecasting. Bulletin of the Disaster Prevention Research Institute, Kyoto Univ., Vol.29, No.1, pp.27–43.Google Scholar
- Kawai, K., Iizuka, A., Hayakawa, E. and Wang, W. (2007): Non-uniform settlement of compacted earth structures caused by the deformation characteristics of unsaturated soil on wetting. Soils and Foundations, Vol.47, No.2, pp.195–206.Google Scholar
- Lenhead, R. J. and Parker, J. C. (1987): A model for hysteretic constitutive relations governing multiphase flow 2. Permeability-saturation relations. Water Resource Research, Vol.23, No.12, pp.2197–2206.Google Scholar
- Mualem, Y. (1976): A new model for predicting the hydraulic conductivity of unsaturated porous media. Water Resource Research, Vol12, No.3, pp.513–522.Google Scholar
- Safety Division, Road Bureau, Ministry of Land, Infrastructure, Transport and Tourism. (2015). Enforcement of new preliminary traffic regulation corresponding to torrential rainfall – Improvement of disaster capture rate and optimization of traffic regulation period-, Road Administration Seminar, Issue 8, pp.1–9 (in Japanese).Google Scholar
- Sugiyama, Y., Kawai, K. and Iizuka, A. (2016): Effects of stress conditions on B-value measurement, Soils and Foundations, Vol.56, No.5, pp.848–860.Google Scholar