DOI QR코드

DOI QR Code

An analysis on stability of riprap considering hydraulic characteristics of flow around joint revetment

연결호안 주변 흐름의 수리적 특성을 고려한 사석호안의 안정성 분석

  • Kim, Sooyoung (Hydro Science and Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology) ;
  • Kim, Hyung-Jun (Hydro Science and Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology) ;
  • Yoon, Kwang Seok (Hydro Science and Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology)
  • 김수영 (한국건설기술연구원 수자원.하천연구소) ;
  • 김형준 (한국건설기술연구원 수자원.하천연구소) ;
  • 윤광석 (한국건설기술연구원 수자원.하천연구소)
  • Received : 2016.10.27
  • Accepted : 2016.11.27
  • Published : 2016.12.31

Abstract

In joint portions of the levee and the barrier, complex 3-dimensional flow was generated and collapse of revetment occurred frequently. For these reasons, it is necessary to install the joint revetment with greater stability as compared with the general revetment at the joint portions. However, design criteria for joint revetment was not presented in River Design Criteria (KWRA, 2009). Therefore it is necessary to research for engineering design of the joint revetment. In this study, hydraulic experiments were performed under various flow conditions in order to realize the collapse conditions of riprap and carried out in 20.0 m straight open channel with one side levee and the width was 4.0 m. The diameter of riprap covered around joint revetment was 0.03 m and the inlet discharges were $0.5{\sim}0.8m^3/s$. The numerical simulations were performed under same conditions with experiment. as results of this numerical simulations, the influence range was confirmed from the distribution of flow characteristics and shear stress. As a result, the riprap diameter of the joint revetment was calculated from 4.1 to 6.9 times greater than that of general revetment. As the inlet discharge was large, the range of vulnerable area was developed long in the downstream direction despite of same withdrawal velocity of riprap. Through this study, the methods of calculating the riprap diameter and influence range were proposed according to hydraulic characteristics of flow around joint revetment. At a later study, if additional experiments about effect of flood plane and various types of barrier is applied, it is expected that rational design method with stability of joint revetment can be proposed.

제방과 보의 접속부에서는 복잡한 3차원이 흐름이 발생하여 붕괴가 자주 발생한다. 따라서 연결부에는 일반적인 호안에 비해 큰 안정성을 가진 연결호안의 설치가 필요하다. 그러나 연결호안에 대한 설계기준은 하천설계기준에 제시되어 있지 않기 때문에 연결호안의 공학적인 설계를 위한 연구가 필요하다. 본 연구에서는 연결호안에 사석을 포설하고 사석의 이탈조건을 파악하기위해 유량을 변화시켜가며 실험을 수행하였으며 실험수로는 폭 4 m, 길이 20 m의 직선수로이며 한쪽에만 제방이 설치되어 있다. 연결호안의 사석직경은 0.03 m 이며 유입유량은 $0.5{\sim}0.8m^3/s$이다. 동일한 조건에 대한 수치모의를 수행하여 연결부에 대한 흐름조건 및 제방 비탈면의 전단응력 등의 분포를 통해 영향범위를 파악하였다. 그 결과 연결호안의 경우 일반호안에 비해 사석직경이 4.1~6.9배 크게 산정되는 것으로 나타났으며 사석의 이탈속도가 같아도 유량이 클수록 취약지역의 범위가 하류방향으로 더 길게 발달하는 것으로 나타났다. 본 연구를 통해 연결호안 주변의 수리학적 특성에 따른 사석직경 및 영향범위를 산정하는 방법을 제안하였으며 추후 고수부지의 영향, 다양한 형식의 보와 호안에 대한 실험과 추가적인 검토가 수행된다면 연결호안의 안정성을 확보 할 수 있는 합리적인 설계방법을 제시할 수 있을 것이라고 기대된다.

Keywords

References

  1. ANSYS Inc. (2010). ANSYS CFX-solver theory guide. ANSYS release 13.0.
  2. Bae, D. W., Kim, H. J., and Yoon, K. S. (2011). "Development of techniques for revetments design around river-crossing structures." Journal of Korean Society of Hazard Mitigation, Vol. 11, No. 6, pp. 293-299. https://doi.org/10.9798/KOSHAM.2011.11.6.293
  3. Escarameia, M. (1998). "River and channel revetment-A design manual." HR Wallingford.
  4. Escarameia, M. and May, R. W. P. (1992). "Channel protectionturbulence downstream of structures. Report SR 313." HR Wallingford.
  5. Japan Institute of Construction Engineering (JICE) (1998). Dynamic Design of Revetments. Sankaido.
  6. Jeong, S. I., Kim, S. Y., Yoon, K. S., and Lee, S. O. (2012). "Estimation of length of connecting revetment around barriers with total head between upstream and downstream." Journal of Korean Society of Hazard Mitigation, Vol. 12, No. 3, pp. 239-246. https://doi.org/10.9798/KOSHAM.2012.12.3.239
  7. Kim, D. H. (2006). "Turbulent model of ANSYS CFX." Proceedings of 4th Annual Conference, Korean Society for Fluid Machinery, Vol. 3, pp. 1227-1231.
  8. Korea Institute of Civil Engineering and Building Technology (KICT) (2006). Development of Design Techniques for Barriers and Drop Structures. Ministry of Construction & Transportation.
  9. Korea Water Resources Association (KWRA) (2009). River Design Criteria.
  10. Maynord, S. T. (1993). Corps Riprap Design Guidance for Channel Protection, Coastal and Shoreline Protection: Erosion Control Using Riprap and Armourstone, pp. 41-52.
  11. Pilarczyk, K. W. (1990). "Stability criteria for revetments, hydraulic engineering." Proceedings of the 1990 National Conference, American Society of Civil Engineers, New York. pp. 245-250.