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Centrifuge Model Analysis on Mooring Line Deformation

닻줄변형에 관한 원심모형해석

  • Han, Heui-Soo (Dept. of Civil Engrg., Kumoh National Uni. of Tec.) ;
  • Cho, Jae-Ho (Dept. of Civil Engrg., Kumoh National Uni. of Tec.) ;
  • Chang, Dong-Hun (Dept. of Civil Engrg., Kumoh National Uni. of Tec.) ;
  • Jeong, Yeon-Koo (Dept. of Civil Engrg., Kumoh National Uni. of Tec.)
  • Published : 2006.09.30

Abstract

Single segmented mooring lines were tested in a geotechnical centrifuge for the purpose of calibrating the analytical solution developed for the analysis and design of various mooring lines associated with underwater drag/permanent anchors. The model mooring lines included steel ball chains and wire cables placed at various depths within the soft clayey seafloor soil. The mooring lines were loaded to preset tensions at the water surface under an elevated acceleration inside the centrifuge to simulate the field stress conditions experienced by the prototype mooring lines. This paper describes the calibration of two factors that are used as part of the input parameters in the analytical solution of mooring lines and considers the effect of chasing wires that were used in the experiment to determine the locations of the mooring lines.

선박을 정착시키기 위하여 해저지반에 관입된 드래그 / 영구앵커와 앵커에 연결된 닻줄의 지지력 및 변형을 해석하여, 기존의 앵커와 닻줄의 분석 및 개발을 위하여 만들어진 해석프로그램을 calibration 하기 위하여 원심모형시험기를 사용한 시험을 하였다. 시험에 사용된 닻줄은 ball chain 및 wire cable로써, 일정한 단면을 가지고 있으며, 해성점토 지반 안에 다양한 깊이로 정착시킨 후 원심모형시험을 실시하였다. 현장응력조건을 모사하기 위하여, 미리 응력을 가한 시험용 닻줄에 단계별 가속을 하였다. 이 논문은 닻줄의 해석을 위한 중요한 두 가지 변수인 닻줄과 지반의 부착력 및 접착면적환산계수를 결정하기 위한 과정을 설명하고자 하였으며, 이로 인한 닻줄의 변형 및 지지력 변화를 규명하였다.

Keywords

References

  1. Bang, S (1996), 'Anchor Mooring Line Computer Program User Manual', Contract Report CR-6020-OCN, Naval Facilities Engineering Service Center
  2. Bang, S (1998), 'Use of Suction Piles for Mooring of Mobile Offshore Bases', Quarterly Progress Report prepared for Naval Facilities Engineering Service Center
  3. Bang, S, and Taylor, RJ, Jie, Y, and Kim, HT (1996), 'Analysis of Anchor Mooring Line in Cohesive Seafloor', Transportation Research Record, No.1526
  4. Brian Watt Associates, Inc (1983), 'A Method for Predicting Drag Anchor Holding Capacity', Report No. CR 83.036
  5. Degenkamp, G, and Dutta, A (1989), 'Soil Resistance to Embedded Anchor Chain in Soft Clay', Journal of Geotechnical Engineering, Vol. 115, No.19
  6. Dunnavant, TW, and Kwan, CTT (1993), 'Centrifuge Modeling and Parametric Analysis of Drag Anchor Behavior', Offshore Technology Conference Paper No.7202
  7. Law, HK., et al. (1994), 'Centrifuge Testing for Dynamic Anchor Line Modeling', A Report submitted to Naval Facilities Engineering Service Center, Univ. of Colorado, Boulder
  8. Vivatrat, V, Valent, PJ, and Ponterio, AA (1982), ''The Influence of Chain Friction on Anchor Pile design', Proc., 14th Annual Offshore Technology Conference, Paper No.4178