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Research Article

Study on Landslide Flume Tests Using Stability Analysis of the Unsaturated Infinite Slope

불포화 무한사면의 안정해석을 활용한 산사태 모형실험에 관한 연구

Hyo-Sung Song1
,
Byung-Gon Chae2
,
Young-Suk Song3
,
Jung-Hae Choi4
,
Won-Gyo Seo5
,
Ik Woo6*
송 효성1
,
채 병곤2
,
송 영석3
,
최 정해4
,
서 원교5
,
우 익6*
1Researcher, Disaster Prevention Research Division, National Disaster Management Research Institute
2Director, Policy & Planning Division, Korea Institute of Geoscience and Mineral Resources
3Head of Geo-Environmental Hazard Research Center, Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources
4Professor, Department of Earth Science Education, Kyungpook National University
5Manager, Office of International Student Affairs, Kyungsung University
6Professor, Department of Architecture & Coastal Construction Engineering, Kunsan National University
1국립재난안전연구원 방재연구실 연구원
2한국지질자원연구원 정책기획본부 본부장
3한국지질자원연구원 지질환경연구본부 지질환경재해연구센터 센터장
4경북대학교 지구과학교육과 교수
5경성대학교 국제 학생지원팀 팀원
6군산대학교 건축 ‧ 해양건설융합공학부 교수
*Corresponding Author
31 December 2019. pp. 541-552
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Abstract

In this study, landslide flume tests were performed to analyze characteristics of ground characteristics and landslide occurrence due to rainfall infiltration. As test materials, weathered granite soil and gneiss soil, the most frequent landslides in Korea, were used, and landslides were triggered by heavy rain (Intensity = 200 mm/hr). The measurement sensors were installed with 3 sets at toe, slope, top part and shallow (GL-0.2 m), middle (GL-0.4 m), and deep (GL-0.6 m) depth in the slope and measured at 10 second intervals. After landslide flume tests, the slope stability analysis was performed by applying the unsaturated soil theory based on the change of ground characteristics and compared with actual landslide occurrence from flume test. As a result of the analysis, factor of safety reflected the landslide occurrence from flume test and factor of safety decreased as rainfall infiltration, leading to slope failure. Finally we compared to the factor of safety below 1 and actual landslide occurrence time, the average difference was 1,600 seconds for weathered granite soil and 5,400 seconds for weathered gneiss soil.

Keywords
landslide
flume test
heavy rainfall
matric suction
factor of safety

본 연구에서는 강우침투에 따른 사면 내 지반특성변화 및 붕괴특성을 파악하기 위해 산사태 모형실험을 수행하였다. 실험재료로는 국내에서 산사태가 가장 빈번하게 발생하는 화강암 풍화토와 편마암 풍화토를 사용하였고, 시간당 200 mm의 극한강우를 살수함으로써 사면붕괴를 유발하였다. 계측기는 모형사면의 선단부, 사면부, 정상부에 심도별로 천부(GL-0.2 m), 중부(GL-0.4 m), 심부(GL-0.6 m)의 위치에 3 set씩 설치하였고, 데이터는 10초 간격으로 측정하였다. 실험이 종료된 후 실험조건별 지반특성변화를 토대로 불포화이론을 적용하여 사면안정해석을 하였으며, 이를 실제 붕괴형태와 비교 ‧ 분석을 하였다. 분석결과 사면안전율은 붕괴형태에 대한 현상을 반영하였고, 강우가 침투함에 따라 급격하게 감소하면서 사면붕괴에 이르는 것으로 나타났다. 또한 사면안전율이 1 이하로 떨어지는 시점과 실제 붕괴시점을 비교해보았을 때 화강암 풍화토의 경우 평균 1,600초, 편마암 풍화토의 경우 평균 5,400초 차이가 나타났다.

키워드
산사태
모형토조
극한강우
모관흡수력
사면안전율
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Information
  • Publisher :Korean Society of Engineering Geology
  • Publisher(Ko) :대한지질공학회
  • Journal Title :The Journal of Engineering Geology
  • Journal Title(Ko) :지질공학
  • Volume : 29
  • No :4
  • Pages :541-552
  • Received Date : 2019-11-29
  • Revised Date : 2019-12-23
  • Accepted Date : 2019-12-23
  • DOI :https://doi.org/10.9720/kseg.2019.4.541
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