The Journal of Engineering Geology (지질공학)

The Korean Society of Engineering Geology (대한지질공학회)
권호 표지
DOI QR코드

DOI QR Code

Estimation of Debris Flow Impact Forces on Mitigation Structures Using Small-Scale Modelling

모형축소실험을 이용한 토석류 방지시설 충격하중 평가

  • Lee, Kyung-Soo (Principal Engineer, Geotechnical R&D Center, DASAN Engineering Co., Ltd.) ;
  • Cho, Seong-Ha (Principal Engineer, Geotechnical R&D Center, DASAN Engineering Co., Ltd.) ;
  • Kim, Jin-Ho (Principal Engineer, Geotechnical R&D Center, DASAN Engineering Co., Ltd.) ;
  • Yoo, Bo-Sun (Principal Engineer, Geotechnical R&D Center, DASAN Engineering Co., Ltd.)
  • Received : 2017.04.05
  • Accepted : 2017.08.28
  • Published : 2017.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

We use small-scale modelling to estimate the impact ofrce of debris flows on erosion control dams (ECD) and ring nets. The results indicate that the viscoelastic debris flows produced impact forces of 4.14, 3.66, 1.66 kN from the bottom to the top of the ECD. Ring net tests produced a similar trend with generally smaller impact forces (2.28, 1.95, and 1.49 kN). Numerical analysis showed that the weight of the ECD (e.g., concrete retaining walls) provided resistance against the debris flow, whereas deformation of the ring net by elastic-elongation and aggregate penetration reduced the impact force by up to 45% compared with that of the ECD.

본 연구에서는 불투과형 사방댐과 링네트에 가해지는 충격하중을 평가하기 위해 토석류 모형축소실험을 수행하였다. 실험 결과, 토석류는 유체와 유사한 거동을 함에 따라 불투과형 사방댐 배면에 가해지는 토석류 충격하중은 하부구간이 4.14 kN로 가장 높게 작용하며 중간, 상부구간이 3.66 kN, 1.66 kN 가해지는 것으로 측정되었다. 링네트 실험결과 또한 불투과형 사방댐 결과와 같이 충격하중은 하부구간이 크며 상부로 갈수록 감소하는 경향을 보인다(2.28 kN, 1.95 kN, 1.49 kN). 수치해석 결과를 이용하여 토석류 흐름에 의한 토석류 방지시설 충격하중 흡수메커니즘을 분석한 결과, 불투과형 사방댐은 콘크리트 옹벽과 같이 구조물 자체의 강성을 이용하여 수평력에 저항하므로 실제 구조물에 작용한 수평력은 이론식과 유사한 결과가 제시되는 반면, 링네트는 강연선 탄성늘음과 네트 전면으로의 입자 투과를 이용하므로 충격하중은 사방댐 결과보다 최대 45% 감소하는 결과가 제시되었다.

Keywords

References

  1. Baek, Y., Choi, Y. C., Kwon, O. I., and Choi, S. I., 2010, Hazard prevention using multi-level debris flow barriers, Journal of Korean Geo-Environmental Society, Korean Geo-Environmental Society, 11(8), 15-23. (in Korea)
  2. Cho, S. H., Yoo, B. S., Kim, J. H., and Lee, K. S., 2016, Performance assessment for debris mitigation structure by using scale model tests, Journal of The Korean Society of Hazard Mitigation, 16(6), 247-260. (in Korea) https://doi.org/10.9798/KOSHAM.2016.16.6.247
  3. Choi, J, S., 2011, Model experiments on characteristics of debris flow behavior by artificial raining, MSc Thesis, Gangwon National University, 25-28. (in Korea)
  4. Fangqiang, W., Hongjuan, Y., Kaiheng, H., and Sergey, C., 2012, Measuring internal velocity of debris flows by temporally correlated shear forces, Journal of Earth Science, 23(3), 373-380. https://doi.org/10.1007/s12583-012-0258-1
  5. Ha, I. S., Seo, M. W., Park, D. S., and Park, D. H., 2006, Application of geotechnical centrifuge, Journal of The Korean Society of Civil Engineers, Korean Society of Civil Engineers, 54(10), 24-35. (in Korea)
  6. Hubl, J., Suda, J., Proske, D., Kaitna, R., and Scheidl, C., 2009, Debris flow impact estimation eleventh international symposium on water management and hydraulic engineering, 137-148.
  7. Hubl, J., Nagl, G., and Suda, J., 2017, Standardized stress model for design of torrential barriers under impact by debris flow, International Journal of Erosion Control Engineering, 10(1), 50-54.
  8. Hwang, Y. C., 2008, Proposal on evaluation system of demage protection method from debris flow, Journal of Korean Geo-Environmental Society, Korean Geo-Environmental Society, 9(4), 26-33. (in Korea)
  9. Jeon, K. J., Kim, G. H., and Yun, C. Y., 2013, Analysis of debris flow type in gangwon province by database construction, Journal of The Korean Society of Civil Engineers, Korean Society of Civil Engineers, 33(1), 171-179. (in Korea) https://doi.org/10.12652/Ksce.2013.33.1.171
  10. Kim, K. H., 2011, The spreading of debris flow in model test and effect of mitigation facilities, PHc Thesis, Sangji University, 62-69. (in Kora)
  11. Lee, C. J. and Yoo, N. J., 2009, A study on debris flow landslide disasters and restoration at inje of gangwon province, Journal of Korean Society of Hazard Mitigation, Korean Society of Hazard Mitigation, 9(1), 99-105. (in Korea)
  12. Lee, K. S., Yoo, B. S., and Cho, S. H., 2015, Debris flow scaled model test development for flexible ring net improvement, Korean Society Civil Engineers 2015 Convention Civil Expo & Conference, 15-16. (in Korea)
  13. Lister, D. R., Morgan, G. C., VanDine, D. F., and Kerr, J. W. G., 1984, Debris torrents in howe sound, british columbia, proceedings, 4th international symposium on landslides, toronto, 649-654.
  14. Lo, D., 2000, Review of natural terrain landslide debris-resisting barrier design, Geotechnical Engineering Office, 8-42.
  15. Ma, H. S. and Jeong, W. O., 2010, Characteristics analysis of debris flow disaster in korean national parks, Journal of The Korean Society of Environmental Restoration Technology, The Korean Society of Environmental Restoration Technology, 13(4), 52-64. (in Korea)
  16. Max, Lee, C. Y., 2014, Mountain landslide disasters, Kuhminsa, 305p.
  17. MLR, 2006, Specification of geological investigation for debris flow stabilization, Natinal Land Resources Department, 32.
  18. Moriguchi, S., Borja, R., Yashima, A., and Sawada, K., 2009, Estimating the impact force generated by granular flow on a rigid obstruction, Acta Geotechnica, 4(1), 57-71. https://doi.org/10.1007/s11440-009-0084-5
  19. Nasmith, H. W., 1972, Engineering geology of the southern cordillera of british columbia, 24th International Geological Congress, Montreal, Quebec, Excursion, 8(8), 34.
  20. NILIM, 2007, Manual of technical standard for designing sabo facilities against debris flow and driftwood, Technical note of NILIM, Natural Institute for Land and Infrastructure Management, Ministry of Land, Infrastructure and Transport, 73.
  21. Park, B. S., 2007, Conditions and improvement of slit eroson control dam, MSc Thesis, Gangwon National University, 11-17. (in Korea)
  22. Park, D. G., Kim, T. H., and Oh, J. R., 2004, A study on the debris-flow and mitigation techniques, Research Report of National Institute for Disaster Prevention, National Institute for Disaster Prevention, 295-317. (in Korea)
  23. Song, B. W., 2010, Countermeasures prefecture and design factor analysis of debris flow, Journal of Korean Geo-Environmental Society, Korean Geo-Environmental Society, 11(1), 15-27. (in Korea)
  24. Song, B. W., Yoon, H. S., and Kim, S. M., 2013, In-situ experiment method on evaluation of debris flow, Journal of Korean Geo-Environmental Society, Korean Geo-Environmental Society, 14(7), 31-38. (in Korea)
  25. SWCB, 2005, Soil and water conservation handbook, Soil and Water Conservation Bureau of the Council of Agriculture, Taiwan and Chinese Soil and Water Conservation Society, 692.
  26. Terzaghi, K., 1950, Mechanisms of landslides, Application of geology to engineering practice, Geological Society of America, Berkley, 83-123.
  27. VanDine, D. F., 1996, Debris flow control structures for forest engineering, Ministry of Forests, 10-62.
  28. Wendeler, C. and Volkwein, A., 2015, Laboratory tests for the optimization of mesh size for flexible debris-flow barriers, Natural Hazards and Earth System Sciences, 15, 2597-2604. https://doi.org/10.5194/nhess-15-2597-2015