Effects of Local Scouring on Load-Bearing Behaviors of Monopile–Friction Wheel Hybrid Foundations on Sandy Deposit Soil under Lateral Loading
Publication: International Journal of Geomechanics
Volume 24, Issue 6
Abstract
This paper focuses on the horizontal bearing behaviors of an innovative type of foundation, the monopile–friction wheel hybrid foundation, for offshore wind turbines (OWTs). First, the scouring morphology of a monopile–friction wheel composite foundation under unidirectional flow is obtained by means of laboratory flume model tests. Then, the effects of key scouring parameters and the height of the loading point are further investigated through numerical simulations in terms of deformations, soil resistance distributions, and bearing ratios. The results indicate that for composite foundations, the effects of scouring parameters and the height of the loading point on the lateral bearing behaviors are not negligible, with the scouring depth having the most significant effect, followed by the scouring angle, and finally the scouring extent. Between them, the friction wheel contributes more than 40% to the bearing capacity while about 50% is borne by the pile side. In addition, the prediction formulas for the bearing ratios are obtained taking into account the scouring pits. The results provide valuable insights into understanding the load-bearing behaviors of composite foundations and their engineering applications.
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Data Availability Statement
All data and models generated or used in this study are available from the corresponding author by request.
Acknowledgments
This research is supported by the National Natural Science Foundation of China (Grant No. 52178329), the science and technology Program of Hunan Provincial Departent of Transportation (Grant No. 201414).
Author contributions: Xinjun Zou: methodology, conceptualization, writing—review and editing, funding acquisition, supervision; Shun Chen: methodology, derivation, visualization, formal analysis, writing—original draft preparation; Xinyao Tu: methodology, formal analysis and writing—review; Zijiang Yang: formal analysis, writing—review and editing.
Notation
The following symbols are used in this paper:
- Dp
- pile diameter;
- Dw
- friction wheel diameter;
- Dwh
- friction wheel diameter;
- Dwhe
- effective friction wheel diameter;
- d
- maximal scouring depth;
- Ep
- elastic modulus of pile;
- e
- loading eccentricity;
- f
- scour angle;
- H
- lateral load;
- Lp
- pile length;
- l
- maximal scouring length;
- Pp
- lateral earth pressure along the pile;
- Pv
- passive earth pressure under the wheel;
- R
- pile radius;
- Sd
- scour depth;
- Sw
- scour extent;
- Swh
- friction wheel square ;
- Swhe
- effective friction wheel square;
- s
- deformation of the friction wheel;
- tw
- friction wheel thickness;
- x
- distance from pile center along 1 → 2;
- y
- distance from pile center along 3 → 4;
- z
- pile buried depth;
- φ
- internal friction angle of the sand; and
- ν
- Poisson’s ratio.
References
Ahmed, S. S., and B. Hawlader. 2016. “Numerical analysis of large-diameter monopiles in dense sand supporting offshore wind turbines.” Int. J. Geomech. 16 (5): 04016018. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000633.
Anastasopoulos, I., and M. Theofilou. 2016. “Hybrid foundation for offshore wind turbines: Environmental and seismic loading.” Soil Dyn. Earthquake Eng. 80: 192–209. https://doi.org/10.1016/j.soildyn.2015.10.015.
API (American Petroleum Institute). 2000. Recommended practice for planning, designing, and constructing fixed offshore platforms-working stress design: Upstream segment. API Recommended Practice 2A-WSD (RP 2A-WSD): Errata and Supplement 1, December 2002. Washington, DC: API.
Arshi, H. S., and K. J. L. Stone. 2012. “Lateral resistance of hybrid monopile-footing foundations in cohesionless soils for offshore wind turbines.” In Offshore site investigation and geotechnics: Integrated technologies-present and future. London, UK: Royal Geographical Society.
Bransby, M. F., and M. F. Randolph. 1998. “Combined loading of skirted foundations.” Géotechnique 48 (5): 637–655. https://doi.org/10.1680/geot.1998.48.5.637.
Bransby, M. F., and G.-J. Yun. 2009. “The undrained capacity of skirted strip foundations under combined loading.” Géotechnique 59 (2): 115–125. https://doi.org/10.1680/geot.2007.00098.
Brown, C., and B. Foley. 2015. Achieving a cost-competitive offshore wind power industry: What is the most effective policy framework?. Oxford, UK: The Oxford Institute for Energy Studies.
Carder, D. R., G. V. R. Watson, R. J. Chandler, and W. Powrie. 1999. “Long-term performance of an embedded retaining wall with a stabilizing base slab.” Proc. Inst. Civ. Eng. Geotech. Eng. 137 (2): 63–74. https://doi.org/10.1680/gt.1999.370201.
Det Norske Veritas. 2014. Design of offshore wind turbine structures. Offshore Standard DNV-OS-J101. Hovik, Norway: Det Norske Veritas.
Ding, H., R. Hu, P. Zhang, and C. Le. 2020. “Load bearing behaviors of composite bucket foundations for offshore wind turbines on layered soil under combined loading.” Ocean Eng. 198: 106997. https://doi.org/10.1016/j.oceaneng.2020.106997.
El-Marassi, M. 2011. Investigation of hybrid monopile-footing foundation systems subjected to combined loading. London, ON: Univ. of Western.
Guo, X., J. Liu, P. Yi, X. Feng, and C. Han. 2022. “Effects of local scour on failure envelopes of offshore monopiles and caissons.” Appl. Ocean Res. 118: 103007. https://doi.org/10.1016/j.apor.2021.103007.
IEA (International Energy Agency). 2022. World energy outlook 2022. Paris: IEA.
Liang, F., C. Wang, M. Huang, and Y. Wang. 2017. “Experimental observations and evaluations of formulae for local scour at pile groups in steady currents.” Mar. Georesour. Geotechnol. 35 (2): 245–255. https://doi.org/10.1080/1064119X.2016.1147510.
Liang, F., C. Wang, and X. Yu. 2019. “Widths, types, and configurations: Influences on scour behaviors of bridge foundations in non-cohesive soils.” Mar. Georesour. Geotechnol. 37 (5): 578–588. https://doi.org/10.1080/1064119X.2018.1460644.
Liang, F., Z. Yuan, X. Liang, and H. Zhang. 2022. “Seismic response of monopile-supported offshore wind turbines under combined wind, wave and hydrodynamic loads at scoured sites.” Comput. Geotech. 144: 104640. https://doi.org/10.1016/j.compgeo.2022.104640.
Nanda Kishore, Y., S. Narasimha Rao, and J. S. Mani. 2009. “The behavior of laterally loaded piles subjected to scour in marine environment.” KSCE J. Civ. Eng. 13: 403–408. https://doi.org/10.1007/s12205-009-0403-2.
Oh, K.-Y., W. Nam, M. S. Ryu, J.-Y. Kim, and B. I. Epureanu. 2018. “A review of foundations of offshore wind energy convertors: Current status and future perspectives.” Renewable Sustainable Energy Rev. 88: 16–36. https://doi.org/10.1016/j.rser.2018.02.005.
Pérez-Collazo, C., D. Greaves, and G. Iglesias. 2015. “A review of combined wave and offshore wind energy.” Renewable Sustainable Energy Rev. 42: 141–153. https://doi.org/10.1016/j.rser.2014.09.032.
Richardson, E. V., and S. R. Davis. 2001. Evaluating scour at bridges. Rep. No. FHWA-NHI-01-001. Washington, DC: Federal Highway Administration, Office of Bridge Technology.
Sheil, B., and W. Finnegan. 2017. “Numerical simulations of wave–structure–soil interaction of offshore monopiles.” Int. J. Geomech. 17 (1): 04016024. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000667.
SIMULIA. 2012. Abaqus 6.11 user’s manual. Providence, RI: SIMULIA.
Soulsby, R. L. 1997. “Dynamics of marine sands: A manual for practical applications.” Oceanogr. Lit. Rev. 9 (44): 947.
Stone, K., T. Newson, and J. Sandon. 2007. “An investigation of the performance of a ‘hybrid’ monopile-footing foundation for offshore structures.” In Offshore site investigation and geotechnics: Confronting new challenges and sharing knowledge. Richardson, TX: OnePetro.
Stone, K. J. L., H. S. Arshi, and L. Zdravkovic. 2018. “Use of a bearing plate to enhance the lateral capacity of monopiles in sand.” J. Geotech. Geoenviron. Eng. 144 (8): 04018051. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001913.
Ti, K. S., B. B. Huat, J. Noorzaei, M. S. Jaafar, and G. S. Sew. 2009. “A review of basic soil constitutive models for geotechnical application.” Electron. J. Geotech. Eng. 14: 1–18.
Tseng, W.-C., Y.-S. Kuo, and J.-W. Chen. 2017. “An investigation into the effect of scour on the loading and deformation responses of monopile foundations.” Energies 10 (8): 1190. https://doi.org/10.3390/en10081190.
Wang, C., X. Yu, and F. Liang. 2017. “A review of bridge scour: Mechanism, estimation, monitoring and countermeasures.” Nat. Hazard. 87: 1881–1906. https://doi.org/10.1007/s11069-017-2842-2.
Wang, S., K. Wei, Z. Shen, and Q. Xiang. 2019. “Experimental investigation of local scour protection for cylindrical bridge piers using anti-scour collars.” Water 11 (7): 1515. https://doi.org/10.3390/w11071515.
Wang, X., and J. Li. 2020. “Parametric study of hybrid monopile foundation for offshore wind turbines in cohesionless soil.” Ocean Eng. 218: 108172. https://doi.org/10.1016/j.oceaneng.2020.108172.
Wang, X., S. Li, and J. Li. 2022a. “Lateral response and installation recommendation of hybrid monopile foundation for offshore wind turbines under combined loadings.” Ocean Eng. 257: 111637. https://doi.org/10.1016/j.oceaneng.2022.111637.
Wang, X., X. Zeng, J. Li, and X. Yang. 2018a. “Lateral bearing capacity of hybrid monopile–frictionwheel foundation for offshore wind turbines by centrifuge modelling.” Ocean Eng. 148: 182–192. https://doi.org/10.1016/j.oceaneng.2017.11.036.
Wang, X., X. Zeng, X. Yang, and J. Li. 2018b. “Feasibility study of offshore wind turbines with hybrid monopile foundation based on centrifuge modeling.” Appl. Energy 209: 127–139. https://doi.org/10.1016/j.apenergy.2017.10.107.
Wang, Y., X. Zhu, Y. Lv, and Q. Yang. 2018c. “Large deformation finite element analysis of the installation of suction caisson in clay.” Mar. Georesour. Geotechnol. 36 (8): 883–894. https://doi.org/10.1080/1064119X.2017.1395496.
Wang, Y., X. Zou, and J. Hu. 2021. “Bearing capacity of single pile‒friction wheel composite foundation on sand-over-clay deposit under VHM combined loadings.” Appl. Sci. 11 (20): 9446. https://doi.org/10.3390/app11209446.
Wang, Y., X. Zou, M. Zhou, and X. Zhang. 2022b. “Failure mechanism and lateral bearing capacity of monopile–friction wheel hybrid foundations in soft-over-stiff soil deposit.” Mar. Georesour. Geotechnol. 40 (6): 712–730. https://doi.org/10.1080/1064119X.2021.1934615.
Wang, Y., X. Zou, M. Zhou, and X. Zhang. 2023. “Capacity and failure mechanism of monopile‒wheel hybrid foundation in clay-overlaying-sand deposits under combined V–HM loadings.” Mar. struct. 90: 103443. https://doi.org/10.1016/j.marstruc.2023.103443.
Wei, K., S. Wang, X. Xiang, and Z. Shen. 2021. “Experimental study on local scour and its protection of offshore wind turbine monopile under ocean current.” [In Chinese.] Acta Energ. Sol. Sin. 9: 338–343. https://doi.org/10.19912/j.0254-0096.tynxb.2019-0959.
Whitehouse, R. 1998. Scour at marine structures: A manual for practical applications. London, UK: Thomas Telford.
Yan, J. B., L. W. Kong, C. F. Xiong, and G. F. Xu. 2023. “Damage analysis of shear mechanical behavior of pile–structural soil interface considering shear rate effect.” Acta Geotech. 18: 1–15. https://doi.org/10.1007/s11440-022-01579-5.
Yang, X., X. Zeng, X. Wang, J. Berrila, and X. Li. 2019. “Performance and bearing behavior of monopile–friction wheel foundations under lateral-moment loading for offshore wind turbines.” Ocean Eng. 184: 159–172. https://doi.org/10.1016/j.oceaneng.2019.05.043.
Yang, X., X. Zeng, X. Wang, and H. Yu. 2018. “Performance of monopile–frictionwheel foundations under lateral loading for offshore wind turbines.” Appl. Ocean Res. 78: 14–24. https://doi.org/10.1016/j.apor.2018.06.005.
Yang, Z., and X. Zou. 2023. “An analytical solution for the horizontal vibration behavior of a cylindrical rigid foundation in poroelastic soil layer.” Earthquake Eng. Struct. Dyn. 52 (5): 1617–1628. https://doi.org/10.1002/eqe.3855.
Yu, T., J. Lian, Z. Shi, and H. Wang. 2016. “Experimental investigation of current-induced local scour around composite bucket foundation in silty sand.” Ocean Eng. 117: 311–320. https://doi.org/10.1016/j.oceaneng.2016.03.045.
Zhang, Q., G. Tang, L. Lu, and F. Yang. 2021. “Scour protections of collar around a monopile foundation in steady current.” Appl. Ocean Res. 112: 102718. https://doi.org/10.1016/j.apor.2021.102718.
Zhang, Q., W. Zhu, B. Gao, G. Ye, D.-s. Jeng, and T. Wang. 2022. “Numerical investigation on horizontal deformation of large diameter monopile under cyclic wave loading with local scour holes.” Ocean Eng. 266: 113059. https://doi.org/10.1016/j.oceaneng.2022.113059.
Zhang, Y., B. Bienen, M. J. Cassidy, and S. Gourvenec. 2011. “The undrained bearing capacity of a spudcan foundation under combined loading in soft clay.” Mar. Struct. 24 (4): 459–477. https://doi.org/10.1016/j.marstruc.2011.06.002.
Zhao, M., L. Cheng, and Z. Zang. 2010. “Experimental and numerical investigation of local scour around a submerged vertical circular cylinder in steady currents.” Coastal Eng. 57 (8): 709–721. https://doi.org/10.1016/j.coastaleng.2010.03.002.
Zhao, M., X. Zhu, L. Cheng, and B. Teng. 2012. “Experimental study of local scour around subsea caissons in steady currents.” Coastal Eng. 60: 30–40. https://doi.org/10.1016/j.coastaleng.2011.08.004.
Zhao, X., P. Zhang, Y. Lv, and H. Ding. 2020. “Scour effects on bearing capacity of composite bucket foundation for offshore wind turbines.” Mar. Georesour. Geotechnol. 38 (2): 223–237. https://doi.org/10.1080/1064119X.2019.1566841.
Zhou, X.-L., D.-S. Jeng, Y.-G. Yan, and J.-H. Wang. 2013. “Wave-induced multi-layered seabed response around a buried pipeline.” Ocean Eng. 72: 195–208. https://doi.org/10.1016/j.oceaneng.2013.06.031.
Zou, X., X. Cao, and C. Zhou. 2020. “Model study on the bearing behavior of V‒H combined loaded pile in sand considering the current effects.” [In Chinese.] Rock Soil Mech. 41 (6): 1855–1864.
Zou, X., X. Cao, C. Zhou, M. Zhou, and X. Zhang. 2021. “Experimental study on the bearing capacity of large-diameter monopile in sand under water flow condition.” Ocean Eng. 224: 108708. https://doi.org/10.1016/j.oceaneng.2021.108708.
Zou, X., S. Chen, Z. Yang, X. Tu, and C. Liang. 2023. “Effects of local scouring on the bearing capacity of monopile‒wheel composite foundations in sandy deposit.” Ocean Eng. 288: 116096. https://doi.org/10.1016/j.oceaneng.2023.116096.
Zou, X., Y. Wang, M. Zhou, and X. Zhang. 2022. “Simulation of monopile‒wheel hybrid foundations under eccentric lateral load in sand-over-clay.” Geomech. Eng. 28 (6): 585–598.
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Published In
International Journal of Geomechanics
Volume 24 • Issue 6 • June 2024
Copyright
© 2024 American Society of Civil Engineers.
History
Received: May 29, 2023
Accepted: Nov 28, 2023
Published online: Mar 19, 2024
Published in print: Jun 1, 2024
Discussion open until: Aug 19, 2024
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