Journal of Korean Society of Disaster and Security (한국방재안전학회논문집)

Korean Society of Disaster & Security (한국방재안전학회)
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Experimental Study of Collapse Delay Effect of Riprap on Dam Slope

사력댐 사석 보호공의 붕괴 지연 효과에 대한 실험 연구

  • Received : 2018.05.10
  • Accepted : 2018.06.28
  • Published : 2018.06.30
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Abstract

The 99.1% of small dam and most of the levees in Korea are soil dam which can be constructed with lower cost and less effort compared with ones made of concrete. However, they are so vulnerable to overflow. Sudden collapses of these strucrues lead to increase flow rate rapidly, which may cause catastrophic problems in downstream regions. In this study, the experimental study on the collapse delay effect of riprap that was laid on slope of soil levee was carried out. A prismatic rectangular open channel was used and three different sizes of the riprap were installed on slope of a scaled earth dam. A new formula for the collapse time of the levee with the installation of riprap was presented, using the previous researches and the dimensional analysis. In this process, an unsteady flow condition was considered to derive the deviation time of the riprap. And additional experiments were conducted to understand the effect of reinforcement of riprap, and it was found that the reinforcement of riprap was more effective than twice sizing of intial riprap. If the collapse time is delayed, EAP (Emergency Action Plan) and forecasting can greatly reduce the degree of flood damage. Also, it will be meaningful that the results of this study are used for river design.

국내 중소규모 저수지의 99.1%는 흙댐으로, 건설비용이 저렴하여 용이한 시공성을 갖고 있다. 그러나 흙댐은 월류에 취약하기 때문에, 홍수 시 급격한 붕괴 가능성이 있다. 이러한 붕괴가 발생할 경우 급격한 홍수량 증가로 이어지기 때문에, 하류 치수 안전성이 위협 받을 가능성이 크다. 이에 본 연구에서는 흙댐 사면에 포설한 사석의 붕괴 지연효과를 실험을 통해 검토하였다. 실험은 사각단면의 직선형 개수로에서 수행하였으며, 보호공 사석의 크기를 3가지로 결정하였다. 선행 연구들과 차이점은 부정류로 실험을 수행한 것이며, 대상은 일반적인 형태의 가물막이로 결정하였다. 실험결과 차원해석 및 선행연구를 이용하여 서석보호공이 포설된 흙댐 붕괴 시간에 대한 새로운 공식을 제시하였다. 또한 사석 보호공이 설치된 경우 실험을 통해 붕괴 지연효과에 대해 검토한 결과 포설된 사석의 2배 이상의 효과가 있는 것으로 확인되었다. 본 연구 결과는 EAP (Emergency Aciton Plan) 수립 및 제방 설계와 같은 하천 계획에 도움이 될 것으로 판단된다.

Keywords

References

  1. ASCE/EWRI Task Committee on Dam/Levee Breaching (2011). Earthen embankment breaching. Journal of hydraulic engineering, 137(12): 1549-1564. https://doi.org/10.1061/(ASCE)HY.1943-7900.0000498
  2. Briaud, J. L. (2008). Case histories in soil and rock erosion: Woodrow Wilson Bridge, Brazos River Meander, ormandy Cliff, and New Orleans levees. J. Geotech. Geoenviron. Eng., 134(10): 1425-1447. https://doi.org/10.1061/(ASCE)1090-0241(2008)134:10(1425)
  3. Chinnarasri, C., Tingsanchali, T., Weesakul, S. and Wongwises, S. (2003). Flow patterns and damage of dike overtopping. Journal of Sediment Research, 18(4): pp. 301-309.
  4. Coleman, S. E., Andrews, D. P. and Webby, M. G. (2002). Overtopping breaching of noncohesive homogeneous embankments. Journal of Hydraulic Engineering, 128(9): pp. 829-838. https://doi.org/10.1061/(ASCE)0733-9429(2002)128:9(829)
  5. Cristofano, E. A. (1965). Method of computing erosion rate for failure of earthfill dams, Denver, CO (U.S. Bureau of Reclamation).
  6. Froehlich, D. C. (2008). Embankment dam breach parameters and their uncertainties. Journal of Hydraulic Engineering, 134(12): pp.1708-1721. https://doi.org/10.1061/(ASCE)0733-9429(2008)134:12(1708)
  7. Han, K. Y., Lee, J. T. and Lee, W. H. (1985) An analysis of outflow hydrograph resulting from an earth Dam-Break, Journal of Korean Society of Civil Engineers, 5(2): pp.41-50.
  8. Hanson, G. J., Temple, D. M., Hunt, S. L., and Tejral, R. D. (2011). Development and characterization of soil aterial parameters for embankment breach. J. Appl. Eng. Agric., 27(4): 587-595. https://doi.org/10.13031/2013.38205
  9. Hartung, D.C. and H. Scheuerlein, (1970). Design of Overflow Rockfill Dams. Proceedings of the 10th International Congress of Large Dams 1: 587-598.
  10. Iksan Regional Construction and Management Administration (2013) Basic Plan of Boseong River, 2013-133, Ministry of Land, Transport and Maritime Affairs, Iksan, p.1257.
  11. Joo, Y. H., Yeo, C. G. and Lee, S. O. (2013) Retardation Effect on the Breach of the Earth Filled Embankment Using the Stiffener During Overtopping, Journal of the Korean Society of Civil Engineers, 33(4): pp.1377-1387. https://doi.org/10.12652/Ksce.2013.33.4.1377
  12. Korean Standards Association (2001) Compaction test of soil (KSF 2312-91).
  13. Khan, D., Ahmad, Z. (2011). Stabilization of angular-shaped riprap under overtopping flows. World Academy of Science, Engineering and Technology, 59: 1153-1157.
  14. Kim, J. H. (2001). Analysis on embankment failure due to overflow. Korea Environmental Industry and Technology Institute, 12(2): pp.97-107.
  15. Lee, D. W. and Noh, J. J. (2012). Behavior of failure of agricultural reservoir embankment due to overtopping, Journal of Agricultural Science, 39(3): pp.427-439.
  16. Lee, S. T. and Lee, J. T. (2001). An experimental study on the collapse phase of a river levees(I) -effect of the geometric characteristics of cross section, 34(2): pp.141-154.
  17. McDonald, T. and Langridge-Monopolis, J. (1984). "Breaching characteristics of dam failures." Journal of Hydraulics Engineering, 110(5): pp. 567-586. https://doi.org/10.1061/(ASCE)0733-9429(1984)110:5(567)
  18. Ministry of Agriculture, Food and Rural Affairs (2008) Statistical year book for Agricultural infrastructure maintenance business, Korea Rural Community Corporation, Uiwang, p.990.
  19. National Disaster Management Research Institute (2002). Damage Area Investigation Report by Typhoon Rusa, 2002-02, Ministry of Government Administration and Home Affairs, Seoul, p.257.
  20. Rouse, H. (1939) An Analysis of Sediment Transportation in the Light of Fluid Turbulence, SCS-TP-25, US Department of Agriculture, Washington, D. C.
  21. Thornton, C. I., Abt, S. R., Clopper, C. E., Scholl, B. N., and Cox, A. L. (2012). Rock stability testing in overtopping flow-2012. Hydraulics Laboratory Technical Rep, 1.
  22. Wan, C. F., and Fell, R. (2004). Investigation of rate of erosion of soils in embankment dams. J. Geotech. Geoenviron. Eng., 130(4): 373-380. https://doi.org/10.1061/(ASCE)1090-0241(2004)130:4(373)
  23. Von Thun, J. L., Gillette, D. R. (1990). Guidance on breach parameters. US Department of the Interior, Bureau of Reclamation.