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현장 함수비 모니터링과 습윤-건조 함수특성곡선을 이용한 산사태 취약성 분석

Landslide Analysis Using the Wetting-Drying Process-Based Soil-Water Characteristic Curve and Field Monitoring Data

  • 이성철 (연세대학교 건설환경공학과) ;
  • 홍문현 (한국산지보전협회) ;
  • 정상섬 (연세대학교 건설환경공학과)
  • 투고 : 2023.03.03
  • 심사 : 2023.05.03
  • 발행 : 2023.05.31

초록

불포화토의 함수특성곡선은 산사태 평가와 토석류 분석에 매우 중요한 요소이다. 본 연구에서는 현장에 적합한 모관흡수력을 통해 산사태 취약성을 분석하기 위하여 함수특성곡선과 체적변형을 고려한 수축시험을 수행하였다. 실험에 사용된 시료는 국내에 분포하는 세립분이 다량함유된 SM계열 화강 풍화토이며, 산사태 해석 시 사용된 강수량의 경우 실측된 데이터를 사용하였다. 실내실험 시 측정된 함수특성곡선은 건조과정에서 발생 된 곡선이며, 체적변형 확인할 수 있는 수축시험을 통하여 습윤과정에서 발생되는 곡선을 재 산정하여 산사태 취약성 분석을 하였다. 본 연구결과 습윤곡선의 안전율이 건조곡선의 안전율보다 낮게 나타남을 알 수 있었으며 그 결과 현장 사면지반의 체적변형을 고려한 모관흡수력 산정이 필요함을 확인 하였다.

This study examined the soil-water characteristic curve (SWCC), considering the volume change, using wetting curves on the field monitoring data of a wireless sensor network. Special attention was given to evaluating the landslide vulnerability by deriving a matric suction suitable for the actual site during the wetting process. Laboratory drying SWCC and shrinkage laboratory tests were used to perform the combined analysis of landslide and debris flow. The results showed that the safety factor of the wetting curve, considering the volume change of soil, was lower than that of the drying curve. As a result of numerical analyses of the debris flow simulation, more debris flow occurred in the wetting curve than in the drying curve. It was also found that the landslide analysis with the drying curve tends to overestimate the actual safety factor with the in situ wetting curve. Finally, it is confirmed that calculating the matric suction through SWCC considering the volume change is more appropriate and reasonable for the field landslide analysis.

키워드

과제정보

본 연구는 정부(교육부)의 재원으로 '한국연구재단의 기초연구사업(2018R1A6A1A08025348)'의 지원을 받아 수행되었으며, 이에 감사드립니다.

참고문헌

  1. Fredlund, D.G. and Xing, A. (1994), Equations for the Soil-water Characteristic Curve, Can.Geotech. J., Vol.31, No.3, pp.521-532. https://doi.org/10.1139/t94-061
  2. Fredlund, D. G., Sheng, D., and Zhao, J. (2011), Estimation of Soil Suction from the Soil-water Characteristic Curve, Canadian geotechnical journal, Vol.48, No.2, pp.186-198. https://doi.org/10.1139/T10-060
  3. Fredlund, M. D., Wilson, G. W., and Fredlund, D. G. (2002, March), Representation and Estimation of the Shrinkage Curve, In Proc., 3rd Int. Conf. on Unsaturated Soils, UNSAT 2002, pp.145-149.
  4. Hong, M. and Jeong, S. (2019), A Combined Method for Rainfallinduced Landslides and Debris Flows in Regional-scale Areas, Journal of the Korean Geotechnical Society, Vol.35, No.10, pp. 17-31. https://doi.org/10.7843/KGS.2019.35.10.17
  5. Jeong, S. and Hong, M. (2022), A Regional-Scale Analysis Based on a Combined Method for Rainfall-Induced Landslides and Debris Flows, In Sustainable Geo-Technologies for Climate Change Adaptation, pp.35-44.
  6. Jeong, S., Hong, M., and Kim, J. (2018), A Wireless Sensor Network Technique and its Application in Regional Landslide Monitoring, Journal of the Korean Geotechnical Society, Vol.34, No.9, pp.19-32. https://doi.org/10.7843/KGS.2018.34.9.19
  7. Jeong, S., Hong, M., and Song, J. (2022), Soil Depth Estimation in Mountainous Areas by Using GIS and Satellite Images, Landslides, Vol.19, No.11, pp.2711-2726. https://doi.org/10.1007/s10346-022-01919-2
  8. Jeong, S., Ko, J., and Kim, J. (2019), The Effectiveness of a Wireless Sensor Network System for Landslide Monitoring, IEEE Access, Vol.8, pp.8073-8086.
  9. Korea Climate Change Assessment Report (2020), https www.si.re.krnode66328
  10. LANDFLOW Program version 3 (2019), LANDFLOW - A Numerical Modeling of GIS-based Rainfall-induced Landslides (Initiation) and Debris Flows, SW Management number: DG-2019-0088.
  11. Lee, I., Cho, W., Kim, Y., and Sung, S. (2003), In-situ Monitoring of Matric suctions in a Weathered Soil Slope, Journal of the Korean Geotechnical Society, Vol.19, No.1, pp.41-49.
  12. Lee, S. C. (2022), Landslides Susceptibility Mapping and Application by Wirelessly Sensed Soil Moisture Monitoring and Modified Soil-Water Characteristic Curve, Domestic master's thesis Graduate School, Yonsei University.
  13. Park, H., Song, Y., and Park, S. (2017), Predicted Hydraulic Behavior in In-Situ Soil Slope Using the Path-Dependent Soil Water Characteristic Curve, Journal of the Korean Society of Civil Engineers, Vol.33, No.4, pp.25-34.
  14. Park, S. and Shin, G. (2009), Stability Analysis on Unsaturated Gneiss Weathered Soil Slopes Considering Wetting Path Soil-water Characteristic Curve, Journal of the Korean Society of Civil Engineers C., Vol.29, No.5C, pp.191-198.
  15. Song, Y. and Park, J. (2021), Development of Landslide Early Warning System Linked with Rainfall Forecast Data, Journal of the Korean Society of Civil Engineers, Vol.69, No.4, pp.54-58.