摘要
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。
Most of the offshore wind turbines are adopted with non-flexible pile foundations with length-to-diameter ratios in the range of 10~20 in China.The applicability of the existing standard methods,which mainly focus on flexible piles with length-to-diameter ratios larger than 20,remains controversial for wind turbine foundations.The finite element analyses are conducted to investigate the response of non-flexible piles under a horizontal load,especially the inclination of pile within a tolerable deformation.Therefore,the Hardening Soil small strain model is adopted to simulate the behavior of sand.A three-dimensional finite element model of steel pipe pile and soil was established for variable parameter analysis,which investigate the effects of relative density and pile diameter on the initial foundation reaction modulus;the reasonableness of the tangent hyperbolic function and hyperbolic function to describe the spring stiffness of the soil(p-y curve)was discussed.Finally,the modified expression for p-y curve that was applicable to non-flexible piles in sand was proposed.The applicability of modified p-y curve was verified by comparing with the simulation results under three different combinations of relative density and pile foundation.The results show that:the relative density and pile diameter are both positively correlated with initial foundation reaction modulus.The hyperbolic function is more suitable for describing p-y curve of the non-flexible pile;the modified p-y curve improves the prediction accuracy of the response of the non-flexible pile under horizontal load.
作者
薛佩佩
王栋
郑敬宾
罗成喜
Xue Peipei;Wang Dong;Zheng Jingbin;Luo Chengxi(The Key Laboratory of Marine Environment and Ecology,Ministry of Education,Ocean University of China,Qingdao 266100,China;Institute of Offshore Geotechnical Engineering,Ocean University of China,Qingdao 266100,China;Power China Zhongnan Engineering Corporation Limited,Changsha 410014,China)
出处
《中国海洋大学学报（自然科学版）》
CAS
CSCD
北大核心
2023年第2期134-140,共7页
Periodical of Ocean University of China
基金
国家自然科学基金项目(42025702,U1806230)资助。
关键词
非柔性桩
初始刚度
P-Y曲线
砂土
有限元法
non-flexible pile
initial stiffness
p-y curve
sand
finite element methods
