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토조실험 장치를 이용한 토사비탈면 표층거동 특성 연구

A Study for Characterization on Shallow Behavior of Soil Slope by Flume Experiments

  • 석재욱 (국립재난안전연구원 방재연구실 지반재난실험팀) ;
  • 박성용 (국립재난안전연구원 방재연구실 지반재난실험팀) ;
  • 나건하 (국립재난안전연구원 방재연구실 지반재난실험팀) ;
  • 강효섭 (국립재난안전연구원 방재연구실 지반재난실험팀)
  • Suk, Jae-wook (Disaster Prevention Research Division, National Disaster Management Research Institute) ;
  • Park, Sung-Yong (Disaster Prevention Research Division, National Disaster Management Research Institute) ;
  • Na, Geon-ha (Disaster Prevention Research Division, National Disaster Management Research Institute) ;
  • Kang, Hyo-Sub (Disaster Prevention Research Division, National Disaster Management Research Institute)
  • 투고 : 2018.09.06
  • 심사 : 2018.09.17
  • 발행 : 2018.09.30

초록

본 연구에서는 급경사지 모형토조 실험을 통해 집중강우에 의한 표층거동 특성 및 체적함수비 변화 특성을 분석하였다. 화강암 풍화토를 대상으로 강우강도(100, 200 mm/hr) 및 초기 지반상태(VWC 7, 14, 26%) 조건에 대한 지표변위 및 체적함수비를 측정하고 영상분석을 위해 실험 전 과정을 비디오 카메라로 촬영하였다. 실험결과 표층붕괴는 후퇴성 붕괴, 전진형 붕괴, 국지적 붕괴의 세가지 형태가 주를 이루며, 후퇴성 붕괴와 전진형 붕괴의 경우 토사가 비탈면 하부까지 퇴적되는 특징으로 인해 상대적으로 큰 피해가 발생할 수 있는 것으로 나타났다. 체적함수비는 초기 조건에 관계없이 일정한 값에서 붕괴가 발생하였으며 건기 시의 지반 조건과 자연상태 조건에서는 체적함수비 증가양상을 통해 표층붕괴를 예측가능한 것으로 나타났다. 강우강도가 큰 경우에 전진형 붕괴가 우세하였으며, 일정 수준이상의 강우강도는 습윤전선 전이에 영향을 미치지 않은 것으로 나타났다.

A flume experiments was used to study the characteristics of the surface displacements and volumetric water contents (VWC) during torrential rain. The surface displacement and VWC of the granite weathered soil were measured for rainfall intensity (100, 200 mm/hr) and initial ground condition (VWC 7, 14, 26%). The test processes were also recorded by video cameras. According to the test results, The shallow failure is classified into three types: retrogressive failure, progressive failure and defined failure. In the case of retrogressive failure and progressive failure, relatively large damage could occur due to the feature that soil is deposited to the bottom of the slope. the shallow failure occurred when the VWC reached a certain value regardless of the initial soil condition. It was found that the shallow failure can be predicted through the increase patton of the VWC under the condition of the ground dry condition (VWC 7%) and the natural condition (VWC 14%). For high rainfall intensity, progressive failure predominated, and rainfall intensity above a certain level did not affect wetting front transition.

키워드

참고문헌

  1. Abramson, L., Lee, T., Sharma, S., Boyce, G., 1996, Slope stability and stabilization methods, John Wiley & Sons, 929.
  2. Acharya, G., Cochrane, T.A., Davies, T., Bowman, E., 2009, The influence of shallow landsides on sediment supply: A flume-based investigation using sandy soil, Engineering Geology, 109, 161-169. https://doi.org/10.1016/j.enggeo.2009.06.008
  3. Chae, B.G., Kim, M.I., 2012, Suggestion of a method for landslide early warning using the change in the volumetric water content gradient due to rainfall infiltration, Environmental Earth Sciences, 66(7), 1973-1986. https://doi.org/10.1007/s12665-011-1423-z
  4. Chae, B.G., Song, Y.S., Seo, Y.S., Cho, Y.C., Kim, W. Y., 2006, A Test for Characterization on Landslides Triggering and Flow Features of Debris using a Flume test Equipment, The Journal of Engineering Geology, 16(3), 275-282 (in Korean with English abstract).
  5. Cho, S.E., Lee, S. R., 2000, Surficial Stability Evaluation of Homegeneous Slopes Considering Rainfall Characteristics, Journal of the Korean Geotechnical Society, 16(5), 107-116 (in Korean with English abstract).
  6. Cochrane, T.A., Jack, G., Weber, P., 2007. Soil armouring, sediment yield, and acid mine drainage from steep under high intensity rainfall in the west coast of New Zealand. 2007 ASABE Annual Meeting. ASABE Paper 072053, Minnesota (USA).
  7. Cruden, D.M., Varnes, D.J., 1996, Landslide types and precesses, Special Report, transportation research board, national academy of science, 247, 36-75.
  8. Huang, C.C., Ju, Y.J., Hwu, L.K., Lee, J.L., 2009, Internal soil moisture and piezometric responses to rainfall induced shallow slope failures, Journal of Hydrology, 370(14), 39-51. https://doi.org/10.1016/j.jhydrol.2009.02.051
  9. Kim, J.H., Jeong, S.S., Park, S.W., Sharma, J., 2004, Influence of rainfall-induced wetting on the stability of slopes in weathered soils, Engineering Geology, 75, 251-262 (in Korean with English abstract). https://doi.org/10.1016/j.enggeo.2004.06.017
  10. Kim, S.W., Jung, S.J., Choi, E.K., Kim, S.H., Lee, K.H., Park, D.G., 2013, An Analysis of the Current Status of Disasters Occurring on the Steep Slopes in Korea, Journal of Environmental Science International, 22(11), 1529-1538. https://doi.org/10.5322/JESI.2013.22.11.1529
  11. Kim, W.Y., Chae B.G., 2009, Characteristics of Rainfall, Geology and Failure Geometry of the Landslide Areas on Natural Terrains, Korea, The Journal of Engineering Geology, 19(3), 331-344 (in Korean with English abstract).
  12. Ministry of Public Safety and Security, 2016, Practical handbook for steep slope, 551-556.
  13. Olivares, L., Damiano, E., 2007. Postfailure mecahnics of landslides: laboratory investigation of flowslides in Pyroclastic soils. Journal of Geotechnical and Geoenvironmental Engineering 133(1), 51-62. https://doi.org/10.1061/(ASCE)1090-0241(2007)133:1(51)
  14. Sasahara, K., 2017, Prediction of the shear deformation of a sandy model slope generated by rainfall based on the monitoring of the shear strain and the pore pressure in the slope, Engineering Geology, 224, 75-86. https://doi.org/10.1016/j.enggeo.2017.05.003
  15. Seo, W.G., Choi, J.H., Chae, B.G., Song Y.S., 2017, Characteristics of Landslide Occurrence and Change in the Matric Suction and Volumetric Water Content due to Rainfall Infiltration, The Journal of Engineering Geology, 27(4), 475-487 (in Korean with English abstract). https://doi.org/10.9720/KSEG.2017.4.475
  16. Song, Y.S., 2013, Stability analysis of the unsaturated infinite slope considering suction stress under steady infiltration condition, Journal of the Korean Geotechnical Society, 29(9), 5-15 (in Korean with English abstract). https://doi.org/10.7843/kgs.2013.29.9.5
  17. Sun, H.W., Wong, H.N., Ho, K.K.S., 1998, Analysis of infiltration in unsaturated ground, In: Proceedings of the annual seminar on slope engineering in Hong Kong, 101-109.
  18. Terlien, M.T.J., 1997. Hydrological landslide triggering in ash-covered slopes of Manizales(Colombia). Geomorphology, 20, 165-175. https://doi.org/10.1016/S0169-555X(97)00022-6
  19. Wang, G., Sassa, K., 2001. Factors affecting rainfall-induced flowslides in laboratory flume tests. Geotechnique, 51(7), 587-599. https://doi.org/10.1680/geot.2001.51.7.587
  20. Wang, G., Sassa, K., 2003. Pore-pressure generation and movement of rainfall-induced landslides: effects of grain size and fine-particle content. Engineering Geology, 69, 109-125. https://doi.org/10.1016/S0013-7952(02)00268-5

피인용 문헌

  1. 토사비탈면 표층붕괴 위험 예측을 위한 체적함수비 증가 특성 연구 vol.30, pp.4, 2020, https://doi.org/10.9720/kseg.2020.4.485