Parametric analyses on dynamic response of an offshore pier under action of wind and wave

Abstract

Offshore structures are constantly subjected to the complex forces of the marine environment, including wind, sea waves, currents, and seismic loadings. Among these, wind and sea wave forces persist throughout the structure’s lifetime. This study proposes a dynamic analysis approach that incorporates both time and frequency domain methods to investigate the structural responses of offshore structures under the combined effects of wind and wave forces. A wind-wave-pier coupling dynamic model is first developed using a small-scale single pier, with corresponding dynamic equilibrium equations established. Fluctuating wind and sea waves are simulated using the weighted amplitude wave superposition (WAWS) method and linear superposition, respectively. Wind and wave load histories are then derived via Fourier transforms. The structural dynamic responses under different loading scenarios (wind only, wave only, and combined wind and wave) are analyzed using the Newmark-β method. Additionally, the effects of varying wind and wave parameters on structural responses are evaluated. The simulation results demonstrate that the structural responses to wind-wave coupling are smaller than the superimposed effects of wind and wave forces acting independently. When wind speeds are relatively low, wave forces dominate structural displacement and serve as the primary source of vibration.

Keywords

coupling actions of wind and wave / weighted amplitude wave superposition / linear superposition / dynamic analysis / Newmark-β method

References

[1] Pierson W J, Moskowitz L. A proposed spectral form for fully developed wind seas based on the similarity theory of S. A. Kitaigorodskii [J]. Journal of Geophysical Research. 1964, 69(24): 5181-5190.

[2] HASSELMANN K. Measurements of wind-wave growth and swell decay during the Joint North Sea Wave Project (JONSWAP) [J]. Ergaenzungsheft zur Deutschen Hydrographischen Zeitschrift, Reihe A, 1973. DOI: 21.11116/0000-0007-DD3C-E.

[3] Goda Y. A comparative review on the functional forms of directional wave spectrum [J]. Coastal Engineering Journal. 1999, 41(1): 1-20.

[4] Davenport A G. The dependence of wind loads on meteorological parameters [J]. Wind Effects on Buildings & Structures. 1967, 1: 19-82

[5] Kareem A C. Dynamic effects of wind on tension leg platforms [C]. Offshore Technology Conference. May 3–6, 1982. 1982, Houston, Texas, OTCOTC-4229-MS

[6] Ochi M K, Shin V S. Wind turbulent spectra for design consideration of offshore structures [C]. Offshore Technology Conference. May 2–5, 1988. 1988, Houston, Texas, OTCOTC-5736-MS

[7] Fang C. Response characteristics and train running performance of long span bridge under correlated wind and waves [D]. 2020, Chengdu, Southwest Jiaotong University(in Chinese)

[8] Song Y-p, Basu B, Zhang Z-let al. . Dynamic reliability analysis of a floating offshore wind turbine under wind-wave joint excitations via probability density evolution method [J]. Renewable Energy. 2021, 168: 991-1014.

[9] Hao Z-z, Tu Q-g, Zhang S-qet al. . Wind-wave relationship model and analysis of typhoon wave fields in the South China Sea from HY-2A satellite observations [J]. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 2020, 13: 4008-4015.

[10] Luo H, Lü H-l, Xie X-zet al. . Study on dynamic response rule of long-span rigid frame bridge subjected to coupled actions of wind and wave loads [J]. Journal of Highway and Transportation Research and Development. 2019, 36(8): 78-85(in Chinese)

[11] Zhu J, Zhang W. Numerical simulation of wind and wave fields for coastal slender bridges [J]. Journal of Bridge Engineering. 2017, 22(3): 04016125.

[12] Zhu J, Wang Y-w, Li Y-let al. . Scour effect on a sea-crossing bridge under combined action of service and extreme seismic loads [J]. Journal of Central South University. 2022, 2982719-2742.

[13] Ti Z-l, Wang Y-f, Song Y-bing. Frequency-domain approach of aero-hydro-elastic response for offshore bottom-mounted slender structures under wind and wave [J]. Ocean Engineering. 2022, 260: 111795.

[14] Li Y-l, Fang C, Wei Ket al. . Frequency domain dynamic analyses of freestanding bridge pylon under wind and waves using a copula model [J]. Ocean Engineering. 2019, 183359-371.

[15] Bozyigit B, Bozyigit I, Prendergast L J. Analytical approach for seismic analysis of onshore wind turbines considering soil-structure interaction [J]. Structures. 2023, 51: 226-241.

[16] Bozyigit B, Bozyigit I, Prendergast L J. Rapid assessment of seismic performance of large monopile-supported offshore wind turbines under scour [J]. European Journal of Mechanics-A/Solids. 2025, 109: 105451.

[17] Bisoi S, Haldar S. Dynamic analysis of offshore wind turbine in clay considering soil-monopile-tower interaction [J]. Soil Dynamics and Earthquake Engineering. 2014, 6319-35.

[18] Feyzollahzadeh M, Mahmoodi M J, Yadavarnikravesh S Met al. . Wind load response of offshore wind turbine towers with fixed monopile platform [J]. Journal of Wind Engineering and Industrial Aerodynamics. 2016, 158: 122-138.

[19] Wei K, Arwade S R, Myers A T. Incremental wind-wave analysis of the structural capacity of offshore wind turbine support structures under extreme loading [J]. Engineering Structures. 2014, 79: 58-69.

[20] Fang C, Xu Y-l, Li Y-le. Optimized C-vine copula and environmental contour of joint wind-wave environment for sea-crossing bridges [J]. Journal of Wind Engineering and Industrial Aerodynamics. 2022, 225: 104989.

[21] Buljac A, Kozmar H, Yang W-xet al. . Concurrent wind, wave and current loads on a monopile-supported offshore wind turbine [J]. Engineering Structures. 2022, 255113950.

[22] Hu Y, Yang J, Baniotopoulos Cet al. . Dynamic analysis of offshore steel wind turbine towers subjected to wind, wave and current loading during construction [J]. Ocean Engineering. 2020, 216108084.

[23] Guo A-x, Liu J-b, Chen W-let al. . Experimental study on the dynamic responses of a freestanding bridge tower subjected to coupled actions of wind and wave loads [J]. Journal of Wind Engineering and Industrial Aerodynamics. 2016, 15936-47.

[24] Bisht R S, Datta T K, Jain A K. Analysis of offshore guyed tower platforms to wind and wave forces [J]. Journal of Energy Resources Technology. 1998, 120(4): 256-262.

[25] Ji C, Leng S, Townsend J Fet al. . Stochastic dynamic response of a sea-crossing suspension bridge with a span over 2000 m subject to coupled wind - wave action [C]. Structures. 202510883076

[26] Yu Y X. Random wave and its applications to engineering [D]. 2003, Dalian, Dalian University of Technology Press(in Chinese)

[27] Bai X-y, Jiang H, Song G-set al. . Extreme responses of sea-crossing bridges subjected to offshore ground motion and correlated extreme wind and wave [J]. Ocean Engineering. 2022, 247: 110710.

[28] JTS 145–2015. Code of hydrology for harbour and waterway [S]. (in Chinese)

[29] Department of the Army Corps of Engineers.. Coastal engineering manual [M]. 2002

[30] MLIT.. Technical standards and commentaries for port and harbor facilities. The overseas coastal area development institute of Japan [S]. 2009

[31] Philippe M, Babarit A, Ferrant P. Modes of response of an offshore wind turbine with directional wind and waves [J]. Renewable Energy. 2013, 49151-155.

[32] Chen S Y, Liu G, Wu H Bet al. . Dynamic analysis of bridge tower under wind and wave action [C]. ISOPE International Ocean and Polar Engineering Conference. 2015, Hawaii, USA, ISOPE

[33] Liu G, Liu T C, Chen S Yet al. . Dynamic elastic response testing method of bridge structure under wind-wave-current action [C]. ISOPE International Ocean and Polar Engineering Conference. 2015, Hawaii, USA, ISOPE

[34] Liu H-y, Geng B-l, Peng C. Experimental study on elastic model of bridge tower under wind, wave and current [J]. Journal of Waterway and Harbor. 2015, 36(6): 461-466

[35] Bai X-d, Guo A-x, Liu Het al. . Experimental investigation on a freestanding bridge tower under wind and wave loads [J]. Structural Engineering and Mechanics. 2016, 57(5): 951-968.

[36] Guo A-x, Liu J-b, Chen W-let al. . Experimental study on the dynamic responses of a freestanding bridge tower subjected to coupled actions of wind and wave loads [J]. Journal of Wind Engineering and Industrial Aerodynamics. 2016, 159: 36-47.

[37] Wei K, Shen Z-h, Ti Z-let al. . Trivariate joint probability model of typhoon-induced wind, wave and their time lag based on the numerical simulation of historical typhoons [J]. Stochastic Environmental Research and Risk Assessment. 2021, 35(2): 325-344.

[38] Ti Z-l, Li Y-l, Qin S-quan. Numerical approach of interaction between wave and flexible bridge pier with arbitrary cross section based on boundary element method [J]. Journal of Bridge Engineering. 2020, 251104020095.

[39] Ti Z-l, Zhang M-j, Li Y-let al. . Numerical study on the stochastic response of a long-span sea-crossing bridge subjected to extreme nonlinear wave loads [J]. Engineering Structures. 2019, 196: 109287.

[40] Hao X-t, Li T-y, Cao Tet al. . Simulation-based study of wind: Wave interactions under various sea conditions [J]. Journal of Hydrodynamics. 2019, 3161148-1152.

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Central South University