DOI QR코드

DOI QR Code

해상교량기초용 대형원형강관 가물막이의 동적 안정성 모니터링을 위한 실내모형실험

Small-Scaled Laboratory Experiments for Dynamic Stability Monitoring of Large Circular Steel Pipe Cofferdam of Marine Bridge Foundation

  • 박민철 (고려대학교 건축사회환경공학부) ;
  • 이종섭 (고려대학교 건축사회환경공학부) ;
  • 김동호 (고려대학교 건축사회환경공학부) ;
  • 유정동 (고려대학교 건축사회환경공학과)
  • Park, Min-Chul (School of Architecture and Civil Engrg., Korea Univ.) ;
  • Lee, Jong-Sub (School of Architecture and Civil Engrg., Korea Univ.) ;
  • Kim, Dongho (School of Architecture and Civil Engrg., Korea Univ.) ;
  • Yu, Jung-Doung (School of Architecture and Civil Engrg., Korea Univ.)
  • 투고 : 2019.11.27
  • 심사 : 2019.12.12
  • 발행 : 2019.12.31

초록

본 연구의 목적은 충격에 의한 모형 원형강관의 동적 반응을 조사하는 것이며, 선박충돌에 의한 대형원형강관의 동적 안정성 모니터링을 위한 기초연구로써 수행되었다. 실내실험은 직경, 두께, 높이가 각각 30cm, 0.4cm, 90cm인 스테인레스 재질의 단본 모형 원형강관과 3개의 세그먼트를 볼트로 조립한 모형 원형강관으로 수행되었다. 각 세그먼트의 높이는 30cm이다. 대형원형강관이 해상에 설치된 것을 모사하기 위하여 모형 원형강관을 가로, 세로, 높이가 각각 1m인 토조에 설치하였으며, 흙의 높이는 23cm로 하였다. 선박 충돌을 모사하기 위하여 모형 원형강관을 해머로 타격하였으며, 토조 내의 수위를 25cm, 40cm, 55cm, 70cm로 변화시키면서 모형 원형강관의 동적 반응 특성을 비교하였다. 실험결과, 수위가 증가할수록 측정된 신호의 에너지가 감소하였으며, 단본의 모형 원형강관보다 볼트로 조립된 모형 원형강관이 더 큰 감소폭을 보였다. 주파수 특성의 경우, 단본 모형 원형강관에서 측정된 주파수 신호는 수위가 증가할수록 우세 주파수가 감소하는 경향을 보였다. 볼트로 조립된 모형 원형강관의 경우도 수위가 증가할수록 우세 주파수가 감소하였다. 하지만, 수위에 따른 우세 주파수의 감소폭이 상대적으로 작았으며, 수위가 상부 세그먼트에 접할 때 높을 때 급격한 감소를 보였다. 본 연구의 결과는 가속도계로 측정된 신호의 에너지와 주파수 변화 특성이 해상교량기초용 가물막이 대형원형강관의 동적 안정성 모니터링에 유용하게 활용될 수 있음을 보여준다.

This study presents dynamic responses of circular pipe models as a part of fundamental studies on dynamic stability monitoring of the large circular steel pipe cofferdam with the ship collision. Small-scaled laboratory experiments are performed with a single and bolted circular steel pipes with a diameter, thickness, and height of 30, 0.4, 90 cm, respectively. The bolted circular steel pipe is configured with three segments of 30 cm in height. Circular steel pipe models are embedded in a soil tank, all 1 m in length, width, and height. The thickness of soil in the soil tank is set at 23 cm. The ship collision is simulated with a hammer impacting. The dynamic responses are investigated with different water levels of 25, 40, 55, and 70 cm. Experimental results show that a signal energy decreases with increasing water level. More sensitive reduction in the energy appears for the bolted circular steel pipe. A predominant frequency decreases with increasing water level for both single and bolted steel pipes. The minor reduction in the frequency appears for the bolted circular steel pipe under the water level of 70 cm. This study suggests that the signal energy and frequency response is useful for the dynamic stability monitoring of the large circular steel pipe cofferdam.

키워드

참고문헌

  1. Bae, Y.G. and Lee, S.L. (2008), "Analysis of Ship Collision Behavior of Pile Supported Structure", Journal of Korean Society of Civil Engineers, Vol.28, No.3A, pp.323-330 (in Korean).
  2. Bae, Y.G. and Lee, S.L. (2013), "Ship Collision Risk Assessment and Sensitivity Analysis for Sea-Crossing Bridges", Journal of the Korean Society of Civil Engineers, Vol.33, No.5, pp.1753-1763 (in Korean). https://doi.org/10.12652/Ksce.2013.33.5.1753
  3. Cho, H.H. (2009). Probability Analysis of Ship-Bridge Collision Using Ship Maneuvering Simulation, Ph.D. Dissertation, Seoul National University, Korea (in Korean).
  4. Choi, J.O. and Kim, H.J. (2018), "Stability Analysis of Large Circular Cofferdam Using Suction", KSCE 2018 Convention (Conference and Civil Expo), Korean Society of Civil Engineers, Gyeongju, Korea, pp.120-121 (in Korean).
  5. Grandt, A. F. (2004), Fundamentals of Structural Integrity: Damage Tolerant Design and Nondestructive Evaluation. John Wiley & Sons, Inc., NJ.
  6. Jeong, Y.J, Kim, J.S., Park, M.S., and Song, S.H. (2017), "Wave and Current-Induced Structural Behavior of Large Circular Marine Structure", KSCE 2017 Convention (Conference and Civil Expo), Korean Society of Civil Engineers, Busan, Korea, pp.1012-1013 (in Korean).
  7. KICT, Korea Institute of Civil Engineering and Building Technology (2015), Planning Research on Development of Marine Bridge Foundation Large Circular Steel Pile Construction Method, Final Report 14RDPP-C090994-01, Korea Agency for Infrastructure Technology Advancement, 268p (in Korean).
  8. Kim, Y.J. and Kim, H.S. (2016), "Construction Technology of Super Long Span Bridge", Review of Architecture and Building Science, Vol.60, No.5, pp.43-47 (in Korean).
  9. Kim, J., Park, M.S., Jeong, Y.J., and Song, S. (2017), "Numerical Study on the Motion of a Large Marine Temporary Structure Using Submerged Cables under Construction", KSCE 2017 Convention (Conference and Civil Expo), Korean Society of Civil Engineers, Busan, Korea, pp.275-276 (in Korean).
  10. Lee, G.H. and Hong, G.Y. (2011). "A Study for the Evaluation of Ship Collision Forces for the design of Bridge Pier", Journal of Korean Society of Civil Engineers, Vol.31, No.3A, pp.199-206 (in Korean). https://doi.org/10.12652/KSCE.2011.31.3A.199
  11. Lee, J.H., Cho, J.W., and Kim, H.M. (2017), "Installation Method of Large Circular Steel Pipe Using Suction Pressure", KSCE 2017 Convention (Conference and Civil Expo), Korean Society of Civil Engineers, Busan, Korea, pp.13-14 (in Korean).
  12. Lee, M.J., Choi, S.K., Choo, H.W., Cho, Y.S., and Lee, W.J. (2008), "Uniformity of Large Gypsum-Cemented Specimens Fabricated by Air Pluviation Method", Journal of the Korean Geotechnical Society, Vol.24, No.1, pp.91-99 (in Korean).
  13. Manen, S.E. and Frandsen, A.G. (1998), "Ship Collision with Bridges, Review of Accidents", Proceedings of the International Symposium on Advances in Ship Collision Analysis, Denmark, pp. 3-11.
  14. Santamarina, J.C., Klein, K.A., and Fam, M.A. (2001), Soils and Waves. John Wiley & Sons, 351 Inc., NJ.
  15. Ssenyondo, V., Tran, V.A., and Kim, S.R. (2017), "Numerical Investigation on Seepage Stability in Offshore Bucket Cut-Off Walls", Journal of the Korean Geotechnical Society, Vol.33, No.11, pp.73-82 (in Korean). https://doi.org/10.7843/kgs.2017.33.11.73
  16. Unnporsson, R. (2013), Hit Detection and Determination in AE Bursts. In: Wojciech Sikorski (ed.) Acoustic Emission: Research and Aapplications. InTech Publishers.
  17. Wang, L., Yang, L., Huang, D., Zhang, Z., and Chen, G. (2008), "An Impact Dynamics Analysis on a New Crashworthy Device against Ship-Bridge Collision", International Journal of Impact Engineering, Vol.35, No.8, pp.895-904. https://doi.org/10.1016/j.ijimpeng.2007.12.005
  18. Yun, D.H., Suh, S.H., and Kim, Y.T. (2016), "Settlement and Scour Characteristics of Artificial Reef According to Reinforced Ground", Journal Of Ocean Engineering And Technology, Vol.30, No.3, pp. 186-193 (in Korean). https://doi.org/10.5574/KSOE.2016.30.3.186
  19. Yun, H., Nayeri, R., Tasbihgoo, F., Wahbeh, M., Caffrey, J., Wolfe, R., Nigbor, R., Masri, S.F., Abdel-Ghaffar, A., and Sheng, L.H. (2008), "Monitoring the Collision of a Cargo Ship with the Vincent Thomas Bridge", Structural Control and Health Monitoring, Vol. 15, No.2, pp.183-206. https://doi.org/10.1002/stc.213
  20. Zheng, Q., Han, B., and Ou, J. (2018), "Ship-Bridge Collision Monitoring System Based on Flexible Quantum Tunneling Composite with Cushioning Capability", Smart Materials and Structures, Vol. 27, No.7, pp.1-9.