Influence of Foundation Nonlinearity on Offshore Towers Response
Publication: Journal of Geotechnical Engineering
Volume 122, Issue 9
Abstract
The response of a fixed, offshore tower is greatly affected by the nonlinear behavior of the supporting piles. An analysis of the foundation piles response to transient dynamic loading that accounts for soil nonlinearity, discontinuity conditions at the pile-soil interface, and group effect is used to assemble the stiffness matrix of the foundation piles. A foundation stiffness matrix is added to the global structural stiffness matrix at the pertinent degrees of freedom (DOF). A model for the evaluation of wave forces on the tower members that takes into account the spatial incoherence effect on wave forces is used in the analysis. Hydrodynamic damping is evaluated, and the effect of the tower foundation behavior on it is assessed. Furthermore, the tower response to random wave forces is conducted, and the effect of foundation parameters on the tower response is examined. It was found that both the hydrodynamic damping and tower response to wave forces are greatly influenced by the foundation nonlinearity and by pile-soil-pile interaction.
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References
1.
Bea, R. G. (1991). “Earthquake geotechnology in offshore structures.”Proc., 2nd Int. Conf. on Recent Advances in Geotech. Earthquake Engrg. and Soil Dyn., No. SOA13, Univ. of Missouri–Rolla, Mo.
2.
Davenport, A. G. (1964). “The distribution of largest values of random function with application to gust loading.”Proc., 28, Instn. of Civ. Engrs., London, U.K.
3.
El-Marsafawi, H., Kaynia, A. M., and Novak, M.(1992). “The superposition approach to pile group dynamics. Piles under dynamic loads.”J. Geotech. Engrg., 34, 114–135.
4.
El Naggar, M. H., and Novak, M.(1994a). “Nonlinear model for dynamic axial pile response.”J. Geotech. Engrg., ASCE, 120(2), 308–329.
5.
El Naggar, M. H., and Novak, M.(1994b). “Nonlinear axial interaction in pile dynamics.”J. Geotech. Engrg., ASCE, 120(4), 678–696.
6.
El Naggar, M. H., and Novak, M. (1995a). “Nonlinear analysis for dynamic lateral pile response.”J. Soil Dyn. and Earthquake Engrg., Accepted for publication.
7.
El Naggar, M. H., and Novak, M.(1995b). “Nonlinear lateral interaction in pile dynamics.”J. Soil Dyn. and Earthquake Engrg., 14(2), 141–157.
8.
El Naggar, M. H., and Novak, M.(1995c). “Effect of foundation nonlinearity on modal properties of offshore towers.”J. Geotech. Engrg., ASCE, 121(9), 660–668.
9.
Foster, E. T.(1970). “Model for nonlinear dynamics of offshore towers.”J. Engrg. Mech. Div., ASCE, 96(1), 41–67.
10.
Mitwally, H., and Novak, M.(1989). “Wave forces on fixed offshore structures in short-crested seas.”J. Engrg. Mech., ASCE, 115(3), 636–655.
11.
Novak, M.(1977). “Vertical vibration of floating piles.”J. Engrg. Mech. Div., ASCE, 103(1), 153–167.
12.
Novak, M., and El Hifnawy, L.(1983). “Effect of soil structure interaction on damping of structures.”J. Earthquake Engrg. and Struct. Dyn., 11, 595–621.
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Copyright © 1996 American Society of Civil Engineers.
History
Published online: Sep 1, 1996
Published in print: Sep 1996
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