International journal of steel structures (국제강구조저널)

Korean Society of Steel Construction (한국강구조학회)
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Feasibility Study of Submerged Floating Tunnels Moored by an Inclined Tendon System

  • Won, Deokhee (Coastal Disaster Prevention Research Center, Korea Institute of Ocean Science and Technology) ;
  • Kim, Seungjun (Department of Construction Safety and Disaster Prevention Engineering, Daejeon University)
  • Received : 2017.12.15
  • Accepted : 2018.06.04
  • Published : 2018.11.30
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Abstract

Concepts of submerged floating tunnels (SFTs) for land connection have been continuously suggested and developed by several researchers and institutes. To maintain their predefined positions under various dynamic environmental loading conditions, the submerged floating tunnels should be effectively moored by reasonable mooring systems. With rational mooring systems, the design of SFTs should be confirmed to satisfy the structural safety, fatigue, and operability design criteria related to tunnel motion, internal forces, structural stresses, and the fatigue life of the main structural members. This paper presents a feasibility study of a submerged floating tunnel moored by an inclined tendon system. The basic structural concept was developed based on the concept of conventional cable-stayed bridges to minimize the seabed excavation, penetration, and anchoring work by applying tower-inclined tendon systems instead of conventional tendons with individual seabed anchors. To evaluate the structural performance of the new type of SFT, a hydrodynamic analysis was performed in the time domain using the commercial nonlinear finite element code ABAQUS-AQUA. For the main dynamic environmental loading condition, an irregular wave load was examined. A JONSWAP wave spectrum was used to generate a time-series wave-induced hydrodynamic load considering the specific significant wave height and peak period for predetermined wave conditions. By performing a time-domain hydrodynamic analysis on the submerged floating structure under irregular waves, the motional characteristics, structural stresses, and fatigue damage of the floating tunnel and mooring members were analyzed to evaluate the structural safety and fatigue performance. According to the analytical study, the suggested conceptual model for SFTs shows very good hydrodynamic structural performance. It can be concluded that the concept can be considered as a reasonable structural type of SFT.

Keywords

Acknowledgement

Supported by : Ministry of Land, Infrastructure and Transport of Korean

References

  1. American Petroleum Institute. (2010). Planning, designing, and constructing tension leg platforms (API RP 2T). Washington DC: API Publishing Services.
  2. Cifuentes, C., Kim, S., Kim, M. H., & Park, W. S. (2015). Numerical simulation of the coupled dynamic response of a submerged floating tunnel with mooring lines in regular waves. Ocean Systems Engineering, 5(2), 109-123. https://doi.org/10.12989/ose.2015.5.2.109
  3. Det Norske Veritas. (2011). Fatigue design of off shore steel structures (DNV-RP-C203). Oslo: DNV.
  4. Garrett, D. L. (1981). Dynamic analysis of slender rods. Journal of Energy Resources Technology, 104(4), 302-306.
  5. Hong, Y., & Ge, F. (2010). Dynamic response and structural integrity of submerged floating tunnel due to hydrodynamic load and accidental load. In Procedia engineering, first international symposium on Archimedes bridge. 4, pp. 35-50.
  6. Jakobsen, B. (2010). Design of the submerged floating tunnel operating under various conditions. In Procedia engineering, first international symposium on Archimedes bridge, 4, pp. 71-79.
  7. Kim, S., Park, W. S., & Won, D. H. (2016). Hydrodynamic analysis of submerged floating tunnel structures by finite element analysis. Journal of the Korean Society of Civil Engineers, 36(6), 955-967. (in Korean). https://doi.org/10.12652/Ksce.2016.36.6.0955
  8. Kim, S., & Won, D. H. (2017). Investigation of fatigue damage of the mooring lines for submerged floating tunnels under irregular waves. Journal of Korean Society of Steel Construction, 29(1), 49-60. (in Korean). https://doi.org/10.7781/kjoss.2017.29.1.049
  9. Korea Institute of Ocean Science and Technology. (KIOST). (2012). "Submerged floating tunnel with a cable-stayed super long-span and a construction method thereof capable of reducing construction costs." Korea Patent, 10-1211491.
  10. Kunisu, H., Mizuno, S., Mizuno, Y., & Saeki, H. (1994). Study on submerged floating tunnel characteristics under the wave condition. In Proceedings of the fourth international off shore and polar engineering conference. ISOPE-I-94-096.
  11. Lu, W., Ge, F., Wang, L., Wu, X., & Hong, Y. (2011). On the slack phenomena and snap force in tethers of submerged floating tunnels under wave conditions. Material Structures, 24(4), 358-376.
  12. Oh, S. H., Park, W. S., Jang, S. C., & Kim, D. H. (2013). Investigation on the behavioral and hydrodynamic characteristics of submerged floating tunnel based on regular wave experiments. Journal of the Korean Society of Civil Engineers, 33(5), 1887-1895. (in Korean). https://doi.org/10.12652/Ksce.2013.33.5.1887
  13. Ostlid, H. (2010). When is SFT competitive? Dynamic response and structural integrity of submerged floating tunnel due to hydrodynamic load and accidental load. In Procedia engineering, first international symposium on archimedes bridge (ISAB - 2010), 4, pp. 3-11.
  14. Pilato, M. D., Perotti, F., & Fogazzi, P. (2008). 3D dynamic response of submerged floating tunnels under seismic and hydrodynamic excitation. Engineering Structures, 30(1), 268-281. https://doi.org/10.1016/j.engstruct.2007.04.001
  15. Remseth, S., Leira, B. J., Okstad, K. M., & Mathisen, K. M. (1999). Dynamic response and fluid/structure interaction of submerged floating tunnels. Computers & Structures, 72, 659-685. https://doi.org/10.1016/S0045-7949(98)00329-0

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