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2021 Vol.37, Issue 6 Preview Page
Comparison of Rainfall Seepage Characteristics of Gneiss and Granite Weathered Soil

편마암풍화토와 화강암풍화토의 강우 침투특성 비교

Young-Suk Song1
,
Yong-Jae Yoo2
,
Tae-Wan Kim2
,
Jae-Hong Kim3*
송 영석1
,
유 용재2
,
김 태완2
,
김 재홍3*
1Member, Principal Researcher, Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources
2Member, Graduate Student, Dept. of Civil and Environmental Engrg., Dongshin Univ.
3Member, Assistant Prof. Dept. of Civil and Environmental Engrg., Dongshin Univ.
1정회원, 한국지질자원연구원 지질환경연구본부 책임연구원
2정회원, 동신대학교 토목환경공학과 석사과정
3정회원, 동신대학교 토목환경공학과 조교수
*Corresponding Author
30 June 2021. pp. 21-28
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Abstract

The factors of landslides depend on rainfall intensity, duration, and the characteristics of the soil slope. The conventional slope stability analysis has been carried out by assuming that the slope is saturated. But, a site slope consisting of unsaturated ground must be imitated and interpreted in order to explain a proper behavior of the slope due to rainfall. In this study, by using two major categories of soils in Korea, such as granite and gneiss weathered soils, landslide model test and numerical analysis have been compared with the difference of seepage and volumetric water content. In general, the permeability of gneiss weathered soil, which contains a lot of fines content, is slower than that of granite weathered soil. As a result, in extreme rainfall, numerical analysis can show results that can penetrate quickly, resulting in saturation or more dangerous collapse.

Keywords
Gneiss weathered soil
Granite weathered soil
Rainfall seepage
Slope stability
Unsaturated soil

산사태의 원인들은 강우강도와 강우지속시간 그리고 사면의 함수특성에 따라 좌우된다. 기존의 사면안정해석에서는 사면을 포화토로 가정하여 해석해왔다. 그러나 강우로 인한 적절한 사면의 거동을 설명하기 위해서는 불포화지반으로 구성되어 있는 현장사면을 모사하여 해석해야 한다. 본 연구에서는 국내 주요한 산지를 구성하고 있는 지반인 화강풍화토와 편마암풍화토를 구분하여 비탈면붕괴에대한 실내모형시험과 수치해석을 병행하여 강우침투와 사면의 안정성에 대해서 분석하고자 하였다. 일반적으로 세립분을 많이 포함하고 있는 편마암풍화토의 투수계수는 화강풍화토의 투수계수보다 느리다. 이러한 조건의 특징을 활용하여 두 가지 다른 풍화토의 침투량을 체적함수비 센서를 활용하여 강우로 인한 표층의 침투특성을 실내시험과 수치해석으로 비교하고자 한다.

References
1
Fredlund, D. G. and Xing, A. (1994), "Equations for the Soil-water Characteristic Curve", Canadian geotechnical Journal, Vol.31, No.3, pp.512-532. 10.1139/t94-061
2
GeoStudio Ver 8.1 (2016), Seepage modelling with SEEP/W, Calgary, Canada.
3
Kim, J. (2002), "Stability Analysis on Unsaturated Weathered Infinite Slopes based on Rainfall-induced Wetting", Master Thesis, Yonsei University, "Influence of rainfall-induced wetting on the stability of slopes in weathered soils", Engineering Geology, pp.251-262. 10.1016/j.enggeo.2004.06.017
4
Kim, J. and Kim, Y. (2013), "Analysis of Effective Stress Parameter on Partially Saturated Soil via Hydro-Mechanical Behaviors", Journal of Korean Geotechnical Society, Vol.27, No.12, pp.117-126. 10.7843/kgs.2011.27.12.117
5
Kim, J., Jeong, S., Park, S., and Sharma, J. (2004), "Influence of Rainfall-induced Wetting on the Stability of Slopes in Weathered Soils", Engineering Geology, pp.251-262. 10.1016/j.enggeo.2004.06.017
6
Korea Institute of Geoscience and Mineral Resources (2016), "Development of Landslide Rapid Detection Technology Based on Real-Time Monitoring", KIGAM Report, Minstry of Science, ICT and Future Planning, p.217.
7
Lu, N., Godt, J. W., and Wu, D. T. (2010), "A Closed-form Equation for Effective Stress in Unsaturated Soil", Water Resources Research, Vol. 46: W05515. 10.1029/2009WR008646
8
Lu, N. and Likos, W. (2006), "Suction Stress Characteristic Curve for Unsaturated Soil", Journal of Geotechnical and Geoenvironmental Engineering, Vol.132, No.2, pp.131-142. 10.1061/(ASCE)1090-0241(2006)132:2(131)
9
Ministry of Land, Transportation and Maritime Affairs (2011), Construction of slope design criteria, guideline, pp.119-133 (in Korean).
10
Ng, C.W.W. and Pang, Y.W. (2000), "Influence of Stress State on Soil-Water Characteristics and Slope Stability", Journal of Geotechnical and Geoenvironmental Engineering, Vol.126, No.2, pp.157-166. 10.1061/(ASCE)1090-0241(2000)126:2(157)
11
Nuth, M. and Laloui, L. (2007), "Effective Stress Concept in Unsaturated Soils: Clarification and Validation of a Unified Framework", International Journal for Numerical and Analytical Methods in Geomechanics, Vol.32, pp.771-801. 10.1002/nag.645
12
Petley, D. N. (2004), The evolution of slope failures: mechanisms of rupture propagation, Natural Hazards and Earth System Sciences, Vol.4, pp.147-152. 10.5194/nhess-4-147-2004
13
van Genuchten, M. (1980), "Closed-form Equation for Predicting the Hydraulic Conductivity of Unsaturated Soils", Soil Science Society of America Journal, Vol.44, No.5, pp.35-53. 10.2136/sssaj1980.03615995004400050002x
Information
  • Publisher :The Korean Geotechnical Society
  • Publisher(Ko) :한국지반공학회
  • Journal Title :Journal of the Korean Geotechnical Society
  • Journal Title(Ko) :한국지반공학회 논문집
  • Volume : 37
  • No :6
  • Pages :21-28
  • Received Date : 2021-04-09
  • Revised Date : 2021-05-12
  • Accepted Date : 2021-05-13
  • DOI :https://doi.org/10.7843/kgs.2021.37.6.21
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