Effects of Sea Water Level Fluctuations on Seismic Response of Jacket Type Offshore Platforms
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 32794
Effects of Sea Water Level Fluctuations on Seismic Response of Jacket Type Offshore Platforms

Authors: M. Rad, M. Dolatshahi Pirooz, M. Esmayili


To understand the seismic behavior of the offshore structures, the dynamic interaction of the water-structure-soil should be assessed. In this regard the role of the water dynamic properties in magnifying or reducing of the effects of earthquake induced motions on offshore structures haven't been investigated in precise manner in available literature. In this paper the sea water level fluctuations effects on the seismic behavior of a sample of offshore structures has been investigated by emphasizing on the water-structure interaction phenomenon. For this purpose a two dimensional finite element model of offshore structures as well as surrounded water has been developed using ANSYS software. The effect of soil interaction with embedded pile foundation has been imposed by using a series of nonlinear springs in horizontal and vertical directions in soil-piles contact points. In the model, the earthquake induced motions have been applied on springs and consequently the motions propagated upward to the structure and surrounded water. As a result of numerical study, the horizontal deformations of the offshore deck as well as internal force and buckling coefficient in structural elements have been recorded and controlled with and without water presence. In part of study a parametric study has been accomplished on sea water level fluctuations and effect of this parameter has been studied on the aforementioned numerical results.

Keywords: Fluid-Structure Interaction, Jacket, Sea Water Level, Seismic Loading.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1079226

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2037


[1] K.J. Venkataramana, and K. Kawano, "Nonlinear dynamics of offshore structures under sea wave and earthquake forces", Sadhana, parts 2-4, 1995,pp 501-512, India
[2] J. Penzien , M. K. Kaul, B. Berge, "Stochastic response of offshore towers to random sea waves and strong motion earthquakes", Computer Structures Jr,1972, pp. 733-756.
[3] R.G. Bea, "Earthquake and wave design criteria for offshore platforms". J. Struct. Div, Am. Soc.,Civ. Eng., 1979, 105(ST2): 401-419.
[4] S. A. Anagnostopoulos, "Wave and earthquake response of offshore structures: Evaluation of modal solutions", J. Struct. Div., Am. Soc. Cir. Eng., 1982, 108(ST10): 2175-2191.
[5] Technical Drawing, "SPD10, BS10 & FSP10 Platforms Field Layout, Drawing No. Sp9/10-PO-IL-D-9640, National Iranian Oil Company
[6] H.J. Bungartz, M. Schäfer, "Fluid-structure Interaction: Modeling, Simulation, Optimization", Springer-Verlag, 2006, ISBN 3-540-34595- 7.
[7] H. Matlock, "Correlations for design of laterally loaded piles in soft clay", Proc. 2nd Annual Offshore Technology Conference, 1970, pp. 577-594.
[8] K. Kayvani, F. Barzegar, "Modeling of Tubular Members in Offshore Steel Jackets under Severe Cyclic Loading", UNICIV Report No. R-324, School of Civil Engineering, The University of New South Wales, December 1993, ISBN No. 858412918.
[9] V.A. Zayas, E.P. Popov, and S.A. Mahin, "Cyclic inelastic buckling of tubular steel Braces", Report No. UCB/EERC-80/16, Earthquake Engineering Research Center, University of California, Berkeley, CA, 1980.
[10] Release 11.0 Documentation for ANSYS, Copyright ┬® 1995-2002.
[11] A. K. Chopra, "Earthquake Response Analysis of Concrete Dams .Advanced Dam Engineering for Design, Construction and Rehabilitation", Von Nostrand Reinhold, 1988.
[12] American Petroleum Institute, Recommended practice for planning, designing and constructing fixed offshore platforms. API Recommended Practice 2A (RP -2A). 21st ed, 2000.