为研究多筒导管架基础在循环荷载作用下的响应特性,在砂土地基中开展物理模型试验,分析了结构循环倾角、固有频率和阻尼比的变化。根据试验结果,提出基础累积转角经验预测公式。结果表明：循环荷载幅值的增大会加快基础倾角的累积速率。基础累积转角与加载次数在双对数坐标系中近似呈线性关系。结构的固有频率在不同循环荷载幅值加载条件下呈现了相似的变化规律,加载初期小幅增大,随着加载持续进行,固有频率急剧下降并围绕某一平均值波动。系统阻尼比在加载初期急剧下降至初始值的约20%,之后剧烈振荡,变化范围最大可达80%。
Abstract
Physical model tests were conducted in sandy soil to study the response characteristics of tripod bucket jacket foundations under cyclic loading. The cyclic rotation angle response, natural frequency, and damping ratio of the structure were analyzed. Based on the test results, an empirical prediction formula for the cumulative rotation angle of the foundation was proposed. The results indicate that an increase in cyclic load amplitude accelerates the accumulation rate of the foundation’s rotation angle. In a log-log coordinate system, the cumulative rotation angle of the foundation and the number of load cycles approximately exhibit a linear relationship. The natural frequency of the structure demonstrates a similar pattern of change under different cyclic load amplitudes： initially, there is a slight increase in the natural frequency, followed by a sharp decrease, and it then fluctuates around a certain average value as cyclic loading continues. The system's damping ratio sharply decreases at the beginning of loading, reducing to about 20% of the initial value, and then undergoes significant oscillations, with a variation of up to 80%.
关键词
海上风电 /
三筒导管架基础 /
循环荷载 /
物理模型试验
Key words
offshore wind power /
tripod bucket jacket foundation /
cyclic loading /
physical model test
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] LEBLANC C, HOULSBY G T, BYRNE B W.Response of stiff piles in sand to long-term cyclic lateral loading[J]. Géotechnique, 2010, 60(2): 79-90.
[2] WANG L Z, ZHOU W J, GUO Z, et al.Frequency change and accumulated inclination of offshore wind turbine jacket structure with piles in sand under cyclic loadings[J]. Ocean engineering, 2020, 217: 108045.
[3] KONG D Q, WEN K, ZHU B, et al.Centrifuge modeling of cyclic lateral behaviors of a tetrapod piled jacket foundation for offshore wind turbines in sand[J]. Journal of geotechnical and geoenvironmental engineering, 2019, 145(11): 04019099.
[4] 余璐庆. 海上风机桶形基础安装与支撑结构动力特性研究[D]. 杭州: 浙江大学, 2014.
YU L Q.Study on dynamic characteristics of bucket foundation installation and supporting structure of offshore fan[D]. Hangzhou: Zhejiang University, 2014.
[5] 罗仑博, 王媛, 黄景琦, 等. 海洋循环荷载对吸力桶基础水平承载力的影响研究[J]. 太阳能学报, 2021, 42(3): 142-147.
LUO L B, WANG Y, HUANG J Q, et al.Study on effects of cyclic loading on lateral capacity of suction bucket foundations[J]. Acta energiae solaris sinica, 2021, 42(3): 142-147.
[6] ZHOU W J, GUO Z, WANG L Z, et al.Numerical model for suction caisson under axial cyclic loadings[J]. Ocean engineering, 2021, 240: 109956.
[7] 汪明元,李娜,程星磊,等. 软黏土中张紧式吸力桶基础循环弱化过程分析[J]. 太阳能学报,2023, 44(11):341-349.
WANG M Y, LI N, CHENG X L, et al.Analysis of cyclic degradation process of tensioned suction bucket foundations in soft clays[J]. Acta energiae solaris sinica, 2023, 44(11): 341-349.
[8] JEONG Y H, LEE S W, KIM J H.Centrifuge modeling for the evaluation of the cyclic behavior of offshore wind turbine with tripod foundation[J]. Applied sciences, 2021, 11(4): 1718.
[9] 陈立,张浦阳. 三筒吸力式导管架基础循环承载特性研究[J]. 太阳能学报,2023. 44(11):382-386.
CHEN L, ZHANG P L.Study on cyclic bearing characteristics of tripod suction bucket foundations[J]. Acta energiae solaris sinica, 2023, 44(11): 382-386.
[10] NIELSEN K, SVENNINGSEN J, BARARI A, et al.On the cyclic stability diagram of offshore wind turbine supported on multiple foundations in saturated dense sand[J]. Engineering failure analysis, 2023, 144: 106926.
[11] NIKITAS G, VIMALAN N J, BHATTACHARYA S.An innovative cyclic loading device to study long term performance of offshore wind turbines[J]. Soil dynamics and earthquake engineering, 2016, 82: 154-160.
[12] 黄玉佩. 大直径单桩基础海上风机支撑结构动力性状[D]. 杭州: 浙江大学, 2017.
HUANG Y P.Dynamic behavior of offshore fan support structure with large diameter single pile foundation[D]. Hangzhou: Zhejiang University, 2017.
[13] LIANG R, YUAN Y, FU D F, et al.Cyclic response of monopile-supported offshore wind turbines under wind and wave loading in sand[J]. Marine georesources & geotechnology, 2021, 39(10): 1230-1243.
[14] VILLALOBOS JARA F, JARA F A V. Model testing of foundations for offshore wind turbines[D]. Oxford: Oxford University, 2006.
[15] LEBLANC C, BYRNE B W, HOULSBY G T.Response of stiff piles to random two-way lateral loading[J]. Géotechnique, 2010, 60(9): 715-721.
[16] BHATTACHARYA S, LOMBARDI D, MUIR WOOD D.Similitude relationships for physical modelling of monopile-supported offshore wind turbines[J]. International journal of physical modelling in geotechnics, 2011, 11(2): 58-68.
[17] GUO Z, YU L Q, WANG L Z, et al.Model tests on the long-term dynamic performance of offshore wind turbines founded on monopiles in sand[J]. Journal of offshore mechanics and Arctic engineering, 2015, 137(4): 041902.
[18] DNV G L.DNVGL-ST-0126: support structures for wind turbines[S]. Oslo, Norway: DNV GL, 2016.
[19] MALEKJAFARIAN A, JALILVAND S, DOHERTY P, et al.Foundation damping for monopile supported offshore wind turbines: a review[J]. Marine structures, 2021, 77: 102937.
[20] VERSTEIJLEN W G, RENTING F W, VAN DER VALK P L C, et al. Effective soil-stiffness validation: shaker excitation of an in situ monopile foundation[J]. Soil dynamics and earthquake engineering, 2017, 102: 241-262.
基金
广东省科技专项资金项目（SDZX2022006）
PDF(2586 KB)
