Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
권호 표지
DOI QR코드

DOI QR Code

Impacts of Rainfall Events and Distribution on Unsaturated Soil Slope Analysis

불포화 토사사면 해석에 대한 강우사상과 분포의 영향

  • 김재홍 (동신대학교 토목공학과) ;
  • 김호겸 (단국대학교 토목환경공학과) ;
  • 김병수 (오카야마대학교 환경이공학부) ;
  • 박성완 (단국대학교 토목환경공학과)
  • Received : 2015.11.23
  • Accepted : 2015.12.30
  • Published : 2016.01.31
Download PDF
⟨ Previous Next ⟩

Abstract

The time distribution of rainfall is one of the most important considerations for evaluating soil slope stability. In order to study the rainfall-induced slope failure, the rainfall pattern has generally been assumed as uniform rainfall intensity for rainfall duration. However, it should be noted that the time distribution of the design rainfall method has a significant effect on the soil slope instability. The study implemented Mononobe, Huff, and uniform method as three types of time distribution method of the design rainfall to estimate the factor of safety of soil slopes by rainfall duration. As a result, the difference of soil suction and unsaturated hydraulic properties in a soil by rainfall pattern was found through the application of an appropriate time distribution method to numerical simulation for rainfall-induced slope stability.

사면 안정성을 평가하기 위해서는 강우의 시간적 분포가 매우 중요한 영향을 끼친다. 강우로 발생하는 사면붕괴를 해석하기 위해서는 강우패턴을 일반적으로 일정한 형태로 가정하고 해석을 수행한다. 그러나 강우의 시간적분포를 적용하는 설계방법은 사면의 불안정성을 평가하기에 중요한 요소이다. 본 연구에서는 강우에 의한 사면파괴를 계산하기 위해 강우의 시간적 분포는 Mononobe 방법과 Huff 4분위 방법을 적용하였다. 그 결과, 표층으로부터의 습윤대 깊이의 차이를 보였으며, 사면의 안전율 계산에서도 강우의 시간적분포가 영향을 끼치고 있음을 확인하였다.

Keywords

References

  1. Chang, Bhum-Soo (2012), "Paradigm Shift to Reduce Upcoming Slope Disasters", Magazine of National Disaster Management Institute, Vol.14, No.4, pp.16-21.
  2. Fredlund, D. G. and Xing, A. (1994), "Equations for the Soil-water Characteristic Curve", Canadian geotechnical Journal, Vol.31, No.3, pp.512-532.
  3. GeoStudio (2012), Version 8.0, User's guide, International Ltd., Calgary, Canada.
  4. Huff, F. A. (1967), "Time Distribution of Rainfall in Heavy Storms", Water Resources Research, Vol.3, No.4, pp.1007-1019. https://doi.org/10.1029/WR003i004p01007
  5. Huff, F. A. (1970), "Time Distribution Characteristics of Rainfall Rates", Water Resources Research, Vol.6, No.2, pp.447-454. https://doi.org/10.1029/WR006i002p00447
  6. Kim, Y. K. (2009), "Soil Slope Design and Stability Evaluation Metholdolgy Considering Hydraulic Conductivity and Rainfall Characteristics", Ph.D Thesis, KAIST.
  7. Kim, H. K. (2014), "Stability Analysis in Unsaturated Soil Slopes Considering Time Distribution of Rainfall", Master Thesis, Dankook University.
  8. Lee, S. R., Kim, Y. K., Choi, J. C., and Oh, J. K. (2006), "Measurements of Variation of Unsaturated Soil Properties in Compacted Road Slope due to Rainfall Infiltration", Proceeding of Korean Society of Civil Engineering, No.10, pp.3865-3868.
  9. Lee, J. S., Song, Y. K., and Kim, Y. T. (2012), "Slope Stability Characteristic of Unsaturated Weathered Granite Soil in Inje considering Antecedent Rainfall", Journal of the Korean Society of Hazard Mitigation, Vol.12, No.4, pp.85-92. https://doi.org/10.9798/KOSHAM.2012.12.4.085
  10. Ministry of Land, Transport and Maritime Affairs (MLTMA-PR, 2011), "Probability Rainfall Table", Avaliable from "www.k-idf.re.kr"
  11. Ministry of Land, Transport and Maritime Affairs (MLTMA, 2012), "Design Standard for Flood Estimation", Korea.
  12. National Disaster Management Institute (2010), "Study on the Steep Slope Information Compilation and Establishment of an Analysis System", Report.
  13. Oh, J. R. (2013), "Analysis of Landslide Triggering Rainfall Threshold for Prediction of Landslide Occurrence", Ph.D. Thesis, Sejong University.
  14. Tsaparas, I., Rahardjo, H., Toll, D. G., and Leong, E. C. (2002), "Controlling Parameters for Rainfall-induced Landslides", Computers and Geotechnics, Vol.29, pp.1-27. https://doi.org/10.1016/S0266-352X(01)00019-2
  15. van Genuchten (1980), "A Closed form Equation for Predicting the Hydraulic Conductivity of Unsaturated Soils", Soil Science Society of America Journal, Vol.44, pp.892-898. https://doi.org/10.2136/sssaj1980.03615995004400050002x