薛佩佩,王栋,郑敬宾,罗成喜

• 1:中国海洋大学海洋环境与生态教育部重点实验室
• 2:中国海洋大学海洋岩土工程研究所
• 3:中国电建中南勘测设计研究院有限公司

摘要(Abstract)：

中国近海风机大多采用长径比10～20范围内的非柔性桩基础，而现有规范方法主要针对长径比大于20的柔性桩，对我国风机基础的适用性一直存在争议。本文利用有限元法研究砂土中非柔性桩的水平受荷响应，主要关注容许范围内的桩基倾斜，因此采用硬化土小应变本构模型描述砂土的应力应变关系。建立钢管桩-土三维有限元模型进行变参数分析，探究土体相对密实度、桩基直径对初始地基反力模量的影响；讨论了正切双曲线函数和双曲线函数描述土体弹簧刚度(即p-y曲线)的合理性；最终提出了适用于砂土中非柔性桩的修正p-y曲线表达式，并通过与三种不同砂土相对密实度与桩基组合工况下的有限元结果对比，验证了修正p-y公式的合理性。结果表明：土体相对密实度、桩基直径与初始地基反力模量均呈正相关；双曲线函数更适合描述非柔性桩的p-y曲线；修正后的p-y公式提高了水平荷载作用下非柔性桩响应的预测精度。

关键词(KeyWords)： 非柔性桩;初始刚度;p-y曲线;砂土;有限元法

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金项目(42025702,U1806230)资助~~

作者(Author): 薛佩佩,王栋,郑敬宾,罗成喜

参考文献(References)：

• [1] API.Geotechnical and Foundation Design Considerations:ANSI/API RP 2GEO-2011[S].Washington:US-ANSI,2011.
• [2] DNV G L.Offshore Soil Mechanics and Geotechnical Engineering[S].[s.l.]:Offshore Standard DNVGL-RP-C212,Edition August,2017.
• [3] Amar Bouzid D.Numerical investigation of large-diameter monopiles in sands:Critical review and evaluation of both API and newly proposed p-y curves[J].International Journal of Geomechanics,2018,18(11):04018141.
• [4] S?rensen S P H.Soil-structure Interaction For Nonslender,Large-Diameter Offshore Monopiles[D].Aalborg:Aalborg University,2012.
• [5] Kallehave D,Thilsted C L B,Liingaard M A.Modification of the API p-y Formulation of Initial Stiffness of Sand[C].OnePetro:Offshore Site Investigation and Geotechnics:Integrated Technologies-Present and Future,2012.
• [6] 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(10):2989-2995.Li W C,Yang M,Zhu B T.Case study of p-y model for short rigid pile in sand[J].Rock and Soil Mechanics,2015(10):2989-2995.
• [7] Wiemann J,Lesny K,Richwien W.Evaluation of the Pile Diameter Effects On Soil-pile Stiffness[C].Wilhelmshaven:Proceedings of the 7th German Wind Energy Conference(DEWEK),2004.
• [8] Reese L C,Cox W R,Koop F D.Analysis of Laterally Loaded Piles in Sand[C].Houston:Proceedings of the 5th Annual Offshore Technology Conference,1974.
• [9] Kim B T,Kim N K,Jin Lee W,et al.Experimental load-transfer curves of laterally loaded piles in Nak-Dong River sand[J].Journal of Geotechnical and Geoenvironmental Engineering,2004,130(4):416-425.
• [10] Klinkvort R T,Hededal O,Springman S M.Scaling issues in centrifuge modelling of monopiles[J].International Journal of Physical Modelling in Geotechnics,2013,13(2):38-49.
• [11] 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 and Geoenvironmental Engineering,2016,142(1):04015058.
• [12] Thieken K,Achmus M,Lemke K.A new static p-y approach for piles with arbitrary dimensions in sand[J].Geotechnique,2015,38(4):267-288.
• [13] Plaxis.Plaxis 3D reference manual 2020[M].[s.l.]:Plaxis Bv,2020.
• [14] Fan C C,Long J H.Assessment of existing methods for predicting soil response of laterally loaded piles in sand[J].Computers and Geotechnics,2005,32(4):274-289.
• [15] Benz T.Small-strain Stiffness of Soils and Its Numerical Consequences[M].Stuttgart:University of Stuttgart,Institute of Geotechnique,2007.
• [16] Achmus M,Thieken K,Lemke K.Evaluation of p-y Approaches for Large Diameter Monopiles in Sand[C].OnePetro:The Twenty-fourth International Ocean and Polar Engineering Conference,2014.
• [17] 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.
• [18] Bolton M D.The strength and dilatancy of sands[J].Geotechnique,1986,36(1):65-78.

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