Document Type : marine engineering


Department of Marine Structures, Faculty of Marine Science and Technology, Science and Research branch, Islamic Azad University, Tehran


Given the worldwide industry progress in the construction of massive concrete structures, it would be a good idea to use concrete gravity base structures (GBS).In this regard, better understanding of thesestructuresregardingtheiradvantages and disadvantages in offshore areas seems necessary.The present study employed MacCammy-Fuchs method, which is based on the size of the structure to the wavelength and the range of Keulegan-Carpenter number; in this method, diffraction theory and Bessel functions are used to compute the velocity potential function and consequently compute the hydrodynamic pressure on the components of the structure.The results of this study with regard to the harmonic dynamic response of the rocking motion of the platform under wave loads revealed that (i) the computed torque value converges to a definite value by decreasing the size of elements,and (ii) Bessel functions can be represented by amplitude and phase functions which have identical performance.The time-history response of the gravitybase structure, and the amplitudechanges of rocking motion relative to frequency and the height of the waves are other results obtained in this study. Finally, the stability index of the GBS shows that the platform is within safe limits.


Abramowitz, M.; Stegun, I. A., (1965). Handbook of Mathematical Functions.New York- Dover Publications.
Boon, C.; Gouvenot, D.; Gau, M.;Geffriaud, H.F., (1977). Stability of gravity type platforms by filling under the raft.Offshore Technology Conference.
Camerlenghi  A.; Cita,  M. B.; Della Vedova  B.; Fusi N.;Mirabile L.; Pellis G., (1995). Geophysical Evidence of Mud Diapirism on the Mediterranean Ridge Accretionary Complex. Marine Geophysical Researches, Volume 17, Issue 2, pp 115–141.
Dean, E. T. R., (2010). Offshore Geotechnical Engineering: Principles and Practice. 1st edition, Thomas Telford Ltd., London, p. 326.
Gerwick, B.C., (2007). Construction of Marine and Offshore Structures, CRC Press, Boca Raton, p. 840.
Glagovsky,V.B., (2012). Estimation of seismic stability of gravity base substructure for fixed offshore platform. Vedeneev Research Institute, St. Petersburg, Russia.
Holand I.; Gudmestad, O. T.; Jersin, E., (2003). Design of Offshore Concrete Structures. Taylor & Francis e-Library.
LotfollahiYhaghin, M. A.; Ahmadi, H., (2011). Dynamics of Offshore Structures.Tabriz University Press. (in Farsi)
McCormick, M. E., (2010). Ocean Engineering Mechanics, Cambridge University Press.
MirzaeeSefat, S.; Ketabdari, M.J., (2003). Dynamic analysis of marine structures using diffraction theory. 9th Marine Industries Conference, Bandar Abbas. (inFarsi).
Mo, O., (1976). Concrete drilling and production platforms: review of construction, installation and commissioning. Proc. Offshore North Sea Technical Conference and Exhibition.
Mogridge, G. R.; Jamieson, W. W., (1976). Wave Forces on Large Circular Cylinders: A Design Method. Hydraulics Laboratory, National Research Council of Canada, Report MH-111.
Reppe, T.; Helsc, E., (1994). Towage and Installation of Concrete Gravity-Based Structures.Offshore Technology Conference.
Saadatpour, M. M., (2007). Dynamics of Structures. Isfahan University Press.
Stansberg, C. T.; Baarholm, R.; Fokk, T.; Gudmestad, O. T.; Haver, S., (2004). Wave amplification and possible deck impact on gravity based structure in  probability extreme crest heights. 23rd International Conference on Offshore Mechanics and Arctic Engineering.
Waltham A.E., (2000). Towards a classification of karst ground conditions.Proc. 2nd Int. Conf. Engineering for Calcareous Sediments, Balkema, Vol. 2.
Wilson, J. F., (2003). Dynamics of Offshore Structures.John Wiley & Sons.
World Meteorological Organization, (1998). Guide to Wave Analysis and Forecasting, WMO-No. 702.
ZareBonadkooki, H., (2014). Study of a single leg concrete structure’s settlement under the effect of wave, current and wind loads in the Persian Gulf. 5th Offshore Industries Conference, Tehran. (in Farsi).
Bruun, P., (1962). Sea-level rise as a cause of shore erosion. Journal Waterways and Harbours Division, 88 (1-3), 117-130.
Cooper, J. A. G.; Pilkey, O. H., (2004). Sea-level rise and shoreline retreat: time to abandon the Bruun Rule. Global and Planetary Change, 43, 157-171.