Study on p-y models for large-diameter pile foundation based on in-situ tests of offshore wind power
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摘要: 近海风电基础结构以大直径钢管桩为主,然而采用的设计方法仍是基于海上油气平台小直径桩试桩试验总结提出的p–y模型,其预测结果相对保守,可靠性值得商榷。鉴于此,提出一种综合考虑桩径和地层深度影响的黏土p–y修正模型,基于海上风电原位试桩数据对比分析API规范推荐的黏土p–y模型和砂土p–y模型,以及黏土p–y修正模型对水平受荷桩的桩侧土体抗力、桩身变形和桩身弯矩预测的准确性。研究结果表明:API规范推荐的黏土p–y模型显著高估了淤泥混砂和黏土的桩周土体抗力,砂土p–y模型的预测值比实测值约高一个数量级;黏土p–y修正模型对淤泥混砂和黏土的桩侧土体抗力有很好的预测性;基于黏土p–y修正模型和Sorensen等提出的砂土p–y模型能够较精准地预测海床地基中的桩身变形和桩身弯矩。Abstract: Large steel pipe pile is the most commonly used foundation structure for offshore wind power. However, the adopted design methods for large-diameter piles are p-y models, which are originally proposed based on many small-diameter pile tests for offshore oil and gas platforms. The prediction precision of the p-y models is relatively conservative, and its reliability is not clear. Thus, a modified p-y model for clay is proposed considering the influences of pile diameter and soil layer depth. Based on the data of in-situ pile tests of offshore wind power, the accuracies of p-y models for clay and sand recommended by the API code and modified p-y model for clay to predict the lateral soil resistance, pile deformation and bending moment of laterally loaded piles are analyzed and compared. The results show that the p-y model for clay recommended by the API code significantly overestimates the soil resistance of silt-sand and clay soil, and the predicted value using the p-y model for sand is about an order of magnitude higher than the measured one. The modified p-y model for clay can precisely predict the soil resistance of silt-sand and clay soil. Based on the modified p-y model for clay and p-y model sand proposed by Sorensen, the deformation and bending moment of piles in multi-layer seabed can be precisely predicted.
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Keywords:
- offshore wind power /
- laterally loaded pile /
- in-situ pile test /
- p-y model
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表 1 岩土材料参数
Table 1 Properties of soil materials
土层名称 γ /(kN·m-3)cu/kPa ε50 /%φ /(°)Es/MPa fak/kPa 淤泥混砂 17.4 15 2.0 — — 50 黏土 18.0 35 2.0 — — 100 中细砂 21.0 — — 33.8 35 270 砂卵砾石 21.5 — — 42.0 60 — 注: γ 为饱和重度;cu为不排水抗剪强度,ε50 为黏土50%应力水平时对应应变值;φ 为内摩擦角;Es为压缩模量;fak为承载力特征值。表 2 试桩试验参数
Table 2 Parameters of test piles
编号 桩径/m 桩长/m 壁厚/mm 桩顶标高/m 桩底标高/m SZ1 2.0 78.5 30 6 -72.5 SZ2 2.0 82.0 30 6 -76.0 -
[1] 朱斌, 熊根, 刘晋超, 等. 砂土中大直径单桩水平受荷离心模型试验[J]. 岩土工程学报, 2013, 35(10): 1807-1815. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201310007.htm ZHU Bin, XIONG Gen, LIU Jin-chao, et al. Centrifuge modelling of a large-diameter single pile under lateral loads in sand[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(10): 1807-1815. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201310007.htm
[2] CHOO Y W, KIM D. Experimental development of the p-y Relationship for large-diameter offshore monopiles in sands: centrifuge tests[J]. Journal of Geotechnical & Geoenvironmental Engineering, 2016, 142(1): 04015058.
[3] LI W, ZHU B, YANG M. Static response of monopile to lateral load in overconsolidated dense sand[J]. Journal of Geotechnical & Geoenvironmental Engineering, 2017, 143(7): 04017026.
[4] 孙希, 黄维平. 基于实测数据的海上风电大直径桩p-y曲线研究[J]. 太阳能学, 2016, 37(1): 216-221. doi: 10.3969/j.issn.0254-0096.2016.01.034 SUN Xi, HUANG Wei-ping. Study on measured p-y curves of large diameter pile foundation of offshore wind power[J]. Acta Energiae Solaris Sinica, 2016, 37(1): 216-221. (in Chinese) doi: 10.3969/j.issn.0254-0096.2016.01.034
[5] BYRNE B W, MCADAM R, BURD H J, et al. New design methods for large diameter piles under lateral loading for offshore wind applications[C]//Third International Symposium on Frontiers in Offshore Geotechnics, 2015, Norway.
[6] BYRNE B W. PISA: New design methods for offshore wind turbine monopiles[C]//8th International Conference for Offshore Site Investigation Geotechnics, 2017, London.
[7] MCADAM R A, BYRNE B W, HOULSBY G T, et al. Monotonic laterally loaded pile testing in a dense marine sand at Dunkirk[J]. Géotechnique, 2019, 70(11): 1-34.
[8] KIM Y, JEONG S, WON J. Effect of lateral rigidity of offshore piles using proposed p-y curves in marine clay[J]. Marine Georesources & Geotechnology, 2009, 27(1): 53-77.
[9] American Petroleum Institute. Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms-Working Stress Design[M]. Washington D C: American Petroleum Institute Publishing Services, 2005.
[10] JIA J. Soil Dynamics and Foundation Modeling: Offshore and Earthquake Engineering[M]. 2018.
[11] STEVENS J B, AUDIBERT J M E. Re-examination of p-y curve formulations[C]//Proceedings of 11th annual offshore technology conference, 1979, Houston.
[12] ONEILL M W, GAZIOGLU S M. An evaluation of p-y relationships in clays. A Report to the API (Prac 82-41-2), University of Houston, Department of Civil Engineering, Research Report No. UHCE-84-3, 1984.
[13] YAN L, BYRNE P M. Lateral pile response to monotonic pile head loading[J]. Canadian Geotechnical Journal, 2011, 29(6): 955-970.
[14] GEORGIADIS M, ANAGNOSTOPOULOS C, SAFLEKOU S. Centrifugal testing of laterally loaded piles in sand[J]. Canadian Geotechnical Journal, 1992, 29(2): 208-216. doi: 10.1139/t92-024
[15] KIM B T, KIM N K, JIN L W, et al. Experimental Load-Transfer Curves of Laterally Loaded Piles in Nak-Dong River Sand[J]. Journal of Geotechnical & Geoenvironmental Engineering, 2004, 130(4): 416-425.
[16] KLINKVORT R T, HEDEDAL O. Effect of load eccentricity and stress level on monopile support for offshore wind turbines[J]. Canadian Geotechnical Journal, 2014, 51(9): 966-974. doi: 10.1139/cgj-2013-0475
[17] WIEMANN J, LESNY K, RICHWIENI W. Evaluation of the pile diameter effects on soil-pile stiffness[C]//Proceedings of the 7th German Wind Energy Conference, 2004, Wilhelmshaven.
[18] SORENSEN S P H. Soil-Structure Interaction for Non-Slender, Large-Diameter Offshore Monopiles[D]. Denmark: Aalborg University, 2012.
[19] KALLEHAVE D, LEBLANC C, LIINGAARD M A. Modification of the API p-y formulation of initial stiffness of sand, offshore site investigation and geotechnics[C]//Integrated Technologies-Present and Future, Society for Underwater Technology, 2012, London.
[20] GUO W D. On limiting force profile, slip depth and response of lateral piles[J]. Computers & Geotechnics, 2006, 33(1): 47-67.
[21] 朱碧堂. 土体的极限抗力与侧向受荷桩性状[D]. 上海: 同济大学, 2005. ZHU Bi-tang. Limiting Force Profile and Response of Laterally Loaded Piles[D]. Shanghai: Tongji University, 2005. (in Chinese)
[22] SORENSEN S P H, IBSEN L B, AUGUSTES A H. Effects of diameter on initial stiffness of P-y curves for large-diameter piles in sand[C]//The European Conference on Numerical Methods in Geotechnical Engineering, 2010, Norway.
[23] MACLELLAND B, FOCHT J A. Soil modulus for laterally loaded piles[J]. ASCE Soil Mechanics and Foundation Division Journal, 1956, 82(4): 1-22.
[24] 王惠初, 武冬青, 田平. 黏土中横向静载桩P-Y曲线的一种新的统一法[J]. 河海大学学报, 1991, 19(1): 9-17. https://www.cnki.com.cn/Article/CJFDTOTAL-HHDX199101001.htm WANG Hui-chu, WU Dong-qing, TIAN Ping. A new united method of P-Y curves of laterally statically loaded piles in clay[J]. Journal of HoHai University, 1991, 19(1): 9-17. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-HHDX199101001.htm
[25] 董爱民. 风电桩基础水平承载力研究[D]. 2017. DONG Ai-min. Research on Lateral Bearing Capacity of Pile Foundation of Wind Power[D]. 2017. (in Chinese)
[26] 海上风力发电场设计标准:GB/T 51308—2019[S]. 2019. Standard for Design of Offshore Wind Farm: GB/T 51308—2019[S]. 2019. (in Chinese)
[27] MATLOCK H. Correlations for design of laterally loaded piles in soft clay[C]//Offshore Technology Conference, 1970, Dallas.
[28] 李卫超, 杨敏, 朱碧堂. 砂土中刚性短桩的p-y模型案例研究[J]. 岩土力学, 2015, 36(10): 2989-2995. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201510039.htm LI Wei-chao, YANG Min, ZHU Bi-tang. Case study of p-y model for short rigid pile in sand[J]. Rock and Soil Mechanics, 2015, 36(10): 2989-2995. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201510039.htm
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