DOI QR코드

DOI QR Code

An Experimental Study to develope the Subsidence Equation for Riprap Protection around the Pier

교각에 설치된 사석보호공의 침하량 산정식 도출에 관한 실험 연구

  • 지운 (명지대학교 토목환경공학과) ;
  • 여운광 (명지대학교 토목환경공학과) ;
  • 이원민 (명지대학교 토목환경공학과) ;
  • 강준구 (한국건설기술연구원 수자원연구부)
  • Received : 2008.09.29
  • Accepted : 2008.12.18
  • Published : 2009.01.31

Abstract

Riprap filter should be installed around the pier to prevent riprap subsidence due to sediment winnowing or leaching between the riprap and bed layers. However, riprap protection without filters is commonly applied in the field because of ambiguous specifications and technical and economical difficulties to install the filter layer. Therefore, the hydraulic experiments were conducted in this study to measure and analyze the riprap subsidence quantitatively with different conditions for thickness of riprap layer, approached velocity, sizes of riprap and bed material. As the velocity was increased and size of bed material and thickness of riprap layer were decreased, the subsidence was increased. Consequently, the dimensionless riprap subsidence equation was derived using the synthesized experimental results. The results of this study could be employed as a standard criterion or predictor to evaluate the subsidence stability.

교각 세굴 방지를 위해 사석보호공을 설치하는 경우 하상의 유사이탈로 인한 보호공의 침하현상이 발생할 수 있으며 따라서 사석층과 하상 사이에 필터층의 설치가 반드시 필요하다. 하지만 국내의 명확하지 않은 필터설치 기준과 설치를 위한 기술적 어려움 그리고 고가의 공사비와 같은 문제점으로 인해 현장에서는 필터 없는 사석보호공을 주로 시공하고 있다. 이에 본 연구는 다양한 조건의 사석 포설두께, 접근 유속, 사석과 하상토의 입경을 갖는 수리실험을 통해 필터층이 없는 사석보호공의 침하량을 정량적으로 측정 및 분석하였으며 실험 결과, 접근유속이 증가할수록, 하상토의 입경이나 포설두께가 감소 할수록 최대침하량은 증가하는 양상을 보였고 일정 시간 후에는 침하량이 최대값에 도달하여 유사이탈이 더 이상 발생하지 않음을 알 수 있었다. 또한 본 논문에서 수행된 실험결과 자료들을 최종적으로 종합하여 하상토 입경 계수가 포함된 필터층 없는 사석보호공의 무차원 침하량 산정식을 제안하였으며 이러한 연구 결과들은 추후 필터층 없이 시공되는 사석 보호공의 침하 안정성 평가를 위한 지표로 활용될 수 있을 것이다.

Keywords

References

  1. 삼성건설JV(2007) 인천대교프로젝트 세굴조사보고서.
  2. 우효섭(2001) 하천수리학. 청문각.
  3. 지운, 여운광, 이원민(2008) 필터 없는 사석보호공의 유사이탈로 인한 침하 안정성 평가를 위한 실험 연구. 한국수자원학회 논문집, 한국수자원학회, 제41권, 4호, pp. 445-454. https://doi.org/10.3741/JKWRA.2008.41.4.445
  4. Aberg, B. (1993) Washout of grains from filtered sand and gravel materials. Journal of Geotechnical Engineering. ASCE, Vol. 119, No. 1.
  5. Chiew, Y.M. (1995) Mechanics of riprap failure at bridge piers. Journal of Hydraulic Engineering. ASCE, Vol. 121, No. 9, pp. 635-643.
  6. CIRIA (2002) Manual on scour at bridges and other hydraulic structures. Construction Industry Research and Information Association, Westminster, London, U.K.
  7. De Abreu-Lima, C. and Morgan, S. (1951) Protection Earth Dams by riprap of Uniform Size. Thesis submitted to the State University of Iowa, Des Moines, Iowa.
  8. FHWA (1989) Design of Riprap Revetment. Hydraulic Engineering Circular No.11, Publication No. FHWA-IP-89-016, Federal Highway Administration, U.S.A.
  9. FHWA (2001) River Engineering for Highway Encroachments. Publication No. FHWA NHI01-004, Federal Highway Administration, U.S.A.
  10. Gregorius, B.H. (1985) Waterway design procedures-Guidelines. Civil Division Publication, Ministry of Works and Development, Hamilton, New Zealand.
  11. Jetter, K. (1951) Tests on Sand Dikes Protected against Erosion by Overflowing Water. Thesis submitted to the State University of Iowa, Des Moines, Iowa.
  12. Karpoff, K.P. (1955) The Use of Laboratory Tests to Develop Design Criteria for Protective Filters. Proceedings of the American Society for Testing and Materials, Vol. 55, No. 4.
  13. Keller, R.J. (2005) Guidelines for the Design of River Bank Stability and Protection using Riprap. Catchment Hydrology, Australia.
  14. Kenney, T.C. and Lau, D. (1985) Internal stability of granular filters. Canadian Geotechnical Journal, Vol. 22, No. 3.
  15. Kenney, T.C., Chahal, R., Chiu, E., Ofoegbu, G.I., Omange, G.N., and Ume, C.A. (1985) Controlling constriction sizes of granular filters. Canadian Geotechnical Journal, Vol. 22, No. 3.
  16. La Fleur, J., Mlynarek, J., and Rollin, A.L. (1989) Filtration of broadly graded cohesionless soils. Journal of Geotechnical Engineering, Vol. 115, No. 12.
  17. Lauchlan, C.S. and Melville, B.W. (2001). Riprap protection at bridge piers. Journal of Hydraulic Engineering, ASCE, Vol. 127, No. 5, pp. 412-418. https://doi.org/10.1061/(ASCE)0733-9429(2001)127:5(412)
  18. Lim, F.H. and Chiew, Y.M. (2001) Parametric study of riprap failure around bridge piers. Journal of Hydraulic Research. ASCE, Vol. 39, No. 1, pp. 61-72. https://doi.org/10.1080/00221680109499803
  19. Manamperi, H.D.S. (1952) Test of Graded Riprap for protection of Erosible Material. Thesis submitted to the State University of Iowa, Des Moines, Iowa.
  20. Melville, B.W. and Coleman S.E. (2000) Bridge Scour. Water Resources Pulications, Highlands Ranch, Colorado, U.S.A.
  21. Sherard, J.L., Dunnigan, L.P., and Talbot, J.R. (1984) Filters for silts and clays. Journal of Geotechnical Engneering, ASCE, Vol. 110, No .6.
  22. Sherman, W.C. (1953) Filter Experiments and Design Criteria. U.S.Army Waterways Experiment Station. Vicksburg, MS.
  23. Terzaghi, K. (1949) Theoretical Soil Mechanics, Wiley, New York.
  24. USBR (1987) Design of Small Dams-Third Edition. the Bureau of Reclamation, U.S.A.
  25. Worman, A. (1989) Riprap protection without filter layers. Journal of Hydraulic Engineering, ASCE, Vol. 115, No. 12, pp. 1615-1630. https://doi.org/10.1061/(ASCE)0733-9429(1989)115:12(1615)
  26. Yang, C.T. (2003) Sediment Transport Theory and Practice.
  27. Zweck, H. and Davidenkoff, R. (1957) Etude experimentale des filters de granulometrie uniforme. Fourth International Conference on Soil Mechanics & Foundation Engineering, American Society of Civil Engineers, New York, N.Y.