Effects of Two-Phase Flow of Water and Air on Shallow Slope Failures Induced by Rainfall: Insights from Slope Stability Assessment at a Regional Scale

Water

Gyu-Hyun Go¹  Sung-Eun Cho²  Byungmin Kim³  Sinhang Kang³ 

[1] Department of Civil Engineering, Kumoh National Institute of Technology, 61 Daehak-ro, Gumi-si, Gyeongbuk 39177, Korea;Department of Civil and Environmental Engineering, Hankyong National University, 327 Jungang-ro, Anseong-si, Gyeonggi 17579, Korea;School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulju-gun, Ulsan 44919, Korea;

关键词: slope stability;    unsaturated soil slope;    rainfall infiltration;    two-phase fluid flow model;   

DOI  :  10.3390/w12030812

来源: DOAJ

【 摘 要 】

Over 160 shallow landslides resulted from heavy rainfall that occurred in 26−27 July 2011 at Umyeon Mountain, Seoul, South Korea. To accurately reflect the fluid flow mechanism in the void spaces of soils, we considered the two-phase flow of water and air for rainfall infiltration analysis using available historical rainfall data, topographic maps, and geotechnical/hydrological properties. Variations in pore water and air pressure from the infiltration analysis are used for slope stability assessment. By comparing the results from numerical models applying single- and two-phase flow models, we observed that air flow changes the rate of increase in pore water pressure, influencing the safety factor on slopes with a low infiltration capacity, where ponding is more likely to occur during heavy rainfall. Finally, several slope failure assessments were conducted to evaluate the usefulness of using the two-phase flow model in forecasting slope stability in conditions of increased rainfall sums. We observed that the two-phase flow model reduces the tendency of over-prediction compared to the single-phase model. The results from the two-phase flow model revealed good agreement with actual landslide events.

【 授权许可】

Unknown