Probabilistic Failure Envelopes of Monopiles in Scoured Seabed Based on a New Nonstationary Random Field Model
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 149, Issue 6
Abstract
Monopiles, which have been most extensively used in the offshore wind industries, are usually subject to threats from local scour. The effects of local scour on the bearing capacity of monopiles have been studied based on deterministic soil properties and local scour dimensions. However, the properties of the seabed soil and the dimensions of the local scour both have uncertainty. In this study, a new nonstationary random field model, which can better simulate the nonstationary characteristics of the seabed clayey soil and result in a safer probabilistic design of foundations, is proposed to characterize the spatial variability of the seabed clayey soil. Then, the effects of the spatial variability of the seabed clayey soil and the uncertainty of the local scour depth on the bearing capacity of monopiles are investigated under both uniaxial loading and vertical-horizontal-moment (VHM) combined loading using the random finite-element method combined with kriging metamodeling technique and Monte Carlo simulation. The undrained shear strength of the seabed clayey soil was simulated with a lognormally distributed nonstationary random field, and the local scour depth was treated as a uniform random variable. The negative correlation between them was also considered. The results show that the factor of safety required for the local scoured seabed decreased from 3.3 to 2.6 as the negative correlation was enhanced, greater than or equal to that [factor of safety ] for the intact seabed. The procedure of analyzing the design failure envelop of a monopile in spatially variable clayey soil with a local scour proposed in this study can provide a reference for geotechnical engineers.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
This research was supported by the National Natural Science Foundation of China (51978129), the Science and Technology Innovation Foundation of Dalian (2020JJ26GX021), and the Fundamental Research Funds for the Central Universities (DUT21ZD210). These supports are gratefully acknowledged.
References
API (American Petroleum Institute). 2011. Geotechnical and foundation design considerations, first ed.. Washington, DC: API.
Baecher, G. B., and J. T. Christian. 2003. Reliability and statistics in geotechnical engineering. New York: Wiley.
Bergado, D. T., B. C. Patron Jr., W. Youyongwatana, and J.-C. Chai. 1994. “Reliability-based analysis of embankment on soft Bangkok clay.” Struct. Saf. 13 (4): 247–266. https://doi.org/10.1016/0167-4730(94)90032-9.
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.
Bush, E., and L. Manuel. 2009. “Foundation models for offshore wind turbines.” In Proc., 47th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition. Reston, VA: American Institute of Aeronautics and Astronautics.
Butterfield, R., G. T. Houlsby, and G. Gottardi. 1997. “Standardized sign conventions and notation for generally loaded foundations.” Géotechnique 47 (5): 1051–1054. https://doi.org/10.1680/geot.1997.47.5.1051.
Cai, Y., M. Bransby, C. Gaudin, and Y. Tian. 2022. “Accounting for soil spatial variability in plate anchor design.” J. Geotech. Geoenviron. Eng. 148 (2): 04021178. https://doi.org/10.1061/(ASCE)GT.1943-5606.0002720.
Cami, B., S. Javankhoshdel, K. K. Phoon, and J. Ching. 2020. “Scale of fluctuation for spatially varying soils: Estimation methods and values.” ASCE-ASME J. Risk Uncertainty Eng. Syst. Part A: Civ. Eng. 6 (4): 03120002. https://doi.org/10.1061/AJRUA6.0001083.
Cassidy, M. J., M. Uzielli, and Y. Tian. 2013. “Probabilistic combined loading failure envelopes of a strip footing on spatially variable soil.” Comput. Geotech. 49 (Apr): 191–205. https://doi.org/10.1016/j.compgeo.2012.10.008.
Ching, J., and T. Schweckendiek. 2021. State-of-the-art review of inherent variability and uncertainty in geotechnical properties and models. London: International Society of Soil Mechanics and Geotechnical Engineering.
Dassault Systèmes. 2014. Abaqus analysis users’ manual, version 6.14. Vélizy-Villacoublay, France: Dassault Systemes Simulia.
Deb, P., and S. K. Pal. 2019. “Numerical analysis of piled raft foundation under combined vertical and lateral loading.” Ocean Eng. 190 (Oct): 106431. https://doi.org/10.1016/j.oceaneng.2019.106431.
DNV (Det Norske Veritas). 2013. Design of offshore wind turbine structures. Hellerup, Denmark: DNV.
Feng, X., M. F. Randolph, S. Gourvenec, and R. Wallerand. 2014. “Design approach for rectangular mudmats under fully three-dimensional loading.” Géotechnique 64 (1): 51–63. https://doi.org/10.1680/geot.13.P.051.
Fugro. 2020. Geotechnical report-synthetic CPT profiles Hollandse Kust (west) Wind Farm Zone-Dutch Sector, North Sea. Leidschendam, Netherlands: Fugro Netherlands Marine B.V.
Graine, N., M. Hjiaj, and K. Krabbenhoft. 2021. “3D failure envelope of a rigid pile embedded in a cohesive soil using finite element limit analysis.” Int. J. Numer. Anal. Methods Geomech. 45 (2): 265–290. https://doi.org/10.1002/nag.3152.
Griffiths, D. V., J. Huang, and G. A. Fenton. 2015. “Probabilistic slope stability analysis using RFEM with non-stationary random fields.” In Geotechnical safety and risk V. Amsterdam, Netherlands: IOS Press.
Guo, X. S., J. Liu, P. Yi, X. W. Feng, and C. C. Han. 2022. “Effects of local scour on failure envelopes of offshore monopiles and caissons.” Appl. Ocean Res. 118 (Jan): 103007. https://doi.org/10.1016/j.apor.2021.103007.
Han, C., K. Shen, W. Li, S. Zhao, J. Wang, J. Liu, and X. Kong. 2021. “Field tests on installation performance of a new hybrid dynamically installed anchor.” [In Chinese.] Chin. J. Geotech. Eng. 43 (9): 1657–1665.
Harris, J. M., and R. J. Whitehouse. 2017. “Scour development around large-diameter monopiles in cohesive soils: Evidence from the field.” J. Waterw. Port Coastal Ocean Eng. 143 (5): 04017022. https://doi.org/10.1061/(ASCE)WW.1943-5460.0000414.
Hokmabadi, A. S., A. Fakher, and B. Fatahi. 2012. “Full scale lateral behavior of monopiles in granular marine soils.” Mar. Struct. 29 (1): 198–210. https://doi.org/10.1016/j.marstruc.2012.06.001.
Hu, Y., and M. F. Randolph. 1998. “H-adaptive FE analysis of elasto-plastic non-homogeneous soil with large deformation.” Comput. Geotech. 23 (1–2): 61–83. https://doi.org/10.1016/S0266-352X(98)00012-3.
ISO. 2016. Petroleum and natural gas industries—Specific requirements for offshore structures—Part 4: Geotechnical and foundation design considerations. ISO 19901-4. Geneva: ISO.
Jiang, S. H., and J. S. Huang. 2018. “Modeling of non-stationary random field of undrained shear strength of soil for slope reliability analysis.” Soils Found. 58 (1): 185–198. https://doi.org/10.1016/j.sandf.2017.11.006.
Jiang, S. H., D. Q. Li, L. M. Zhang, and C. B. Zhou. 2014. “Slope reliability analysis considering spatially variable shear strength parameters using a non-intrusive stochastic finite element method.” Eng. Geol. 168 (Jan): 120–128. https://doi.org/10.1016/j.enggeo.2013.11.006.
Li, D. Q., S. H. Jiang, Z. J. Cao, W. Zhou, and L. M. Zhang. 2015. “A multiple response-surface method for slope reliability analysis considering spatial variability of soil properties.” Eng. Geol. 187 (Mar): 60–72. https://doi.org/10.1016/j.enggeo.2014.12.003.
Li, D. Q., X. H. Qi, K. K. Phoon, L. M. Zhang, and C. B. Zhou. 2014. “Effect of spatially variable shear strength parameters with linearly increasing mean trend on reliability of infinite slopes.” Struct. Saf. 49 (1): 45–55. https://doi.org/10.1016/j.strusafe.2013.08.005.
Liang, F. Y., H. Zhang, and S. Chen. 2018. “Effect of vertical load on the lateral response of offshore piles considering scour-hole geometry and stress history in marine clay.” Ocean Eng. 158 (Jun): 64–77. https://doi.org/10.1016/j.oceaneng.2018.03.070.
Liu, J., X. S. Guo, and P. Yi. 2023. “Probabilistic approach to the stability analysis of caisson foundations under combined loading in spatially variable soil.” Appl. Ocean Res 134 (May): 103509. https://doi.org/10.1016/j.apor.2023.103509.
Liu, J., M. Li, Y. Hu, and C. Han. 2017. “Bearing capacity of rectangular footings in uniform clay with deep embedment.” Comput. Geotech. 86 (Jun): 209–218. https://doi.org/10.1016/j.compgeo.2017.01.019.
Lumb, P. 1966. “The variability of natural soils.” Can. Geotech. J. 3 (2): 74–97. https://doi.org/10.1139/t66-009.
Mana, D. S. K., S. Gourvenec, and M. F. Randolph. 2010. “A numerical study of the vertical bearing capacity of skirted foundations.” In Proc., 2nd Int. Symp. on Frontiers in Offshore Geotechnics, 433–438. London: Taylor & Francis. https://doi.org/10.1201/b10132-52.
Melling, G. J. 2014. “Hydrodynamic and geotechnical controls of scour around offshore monopiles.” Ph.D. thesis, Faculty of Natural and Environmental Sciences, Ocean and Earth Sciences, Univ. of Southampton.
Molinas, A., S. Jones, and M. Hosny. 1999. “Effects of cohesive material properties on local scour around piers.” Transp. Res. Rec. 1690 (1): 164–174. https://doi.org/10.3141/1690-19.
Musial, W., P. Spitsen, P. Beiter, P. Duffy, M. Marquis, A. Cooperman, R. Hammond, and M. Shields. 2021. Offshore wind market report: 2021 edition. Golden, CO: National Renewable Energy Laboratory.
Oguz, E. A. 2017. “Spatial probabilistic evaluation of sea bottom soil properties and its effect on foundation design.” M.Sc. thesis, Dept. of Civil Engineering, Middle East Technical Univ.
Phoon, K. K., and F. H. Kulhawy. 1999. “Characterization of geotechnical variability.” Can. Geotech. J. 36 (4): 612–624. https://doi.org/10.1139/t99-038.
Poulos, H. G. 1988. Marine geotechnics. London: Unwin Hyman.
Rambabu, M., S. Narasimha Rao, and V. Sundar. 2003. “Current-induced scour around a vertical pile in cohesive soil.” Ocean Eng. 30 (7): 893–920. https://doi.org/10.1016/S0029-8018(02)00063-X.
Randolph, M. F., and S. Gourvenec. 2011. Offshore geotechnical engineering. London: Spon.
Shen, Z., Q. Pan, S. Chian, S. Gourvenec, and Y. Tian. 2021. “Probabilistic failure envelopes of strip foundations on soils with non-stationary characteristics of undrained shear strength.” Géotechnique. https://doi.org/10.1680/jgeot.21.00169.
Tan, M. X., Y. F. Li, P. Yi, and J. Liu. 2022. “Vertical bearing capacity of foundations with large embedment depth in normally consolidated clay.” J. Geotech. Geoenviron. Eng. 148 (11): 06022012. https://doi.org/10.1061/(ASCE)GT.1943-5606.0002885.
Uzielli, M., G. Vannucchi, and K. K. Phoon. 2005. “Random field characterisation of stress-nomalised cone penetration testing parameters.” Géotechnique 55 (1): 3–20. https://doi.org/10.1680/geot.2005.55.1.3.
Wang, C., Y. Yuan, W. Zhu, C. Wang, and X. Yu. 2023. “A probabilistic strategy to evaluate scour around bridge deepwater foundations considering a reliability assessment.” Mar. Georesour. Geotechnol. 41 (1): 54–66. https://doi.org/10.1080/1064119X.2021.2011505.
Whitehouse, R. J. S. 1998. Scour at marine structures: A manual for practical applications. London: Thomas Telford.
Wind Europe. 2021. Offshore wind in Europe—Key trends and statistics 2020. Brussels, Belgium: WindEurope.
Yu, J., H. Wang, M. Huang, and C. Leung. 2021. “Upper-bound analysis of laterally loaded rigid monopiles in clay with linearly increasing strength.” Can. Geotech. J. 58 (9): 1289–1304. https://doi.org/10.1139/cgj-2020-0102.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 149 • Issue 6 • June 2023
Copyright
© 2023 American Society of Civil Engineers.
History
Received: Jul 11, 2022
Accepted: Feb 14, 2023
Published online: Apr 12, 2023
Published in print: Jun 1, 2023
Discussion open until: Sep 12, 2023
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.
Cited by
- Jun Liu, Xinshuai Guo, Juncheng Li, Ping Yi, Baisong Wang, Study of Site Investigation Sample Quality and Worst-Case Scale of Fluctuation for Monopiles Based on Conditional Random Fields, ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part A: Civil Engineering, 10.1061/AJRUA6.RUENG-1193, 10, 3, (2024).