粉土海床中风机单桩基础水平承载特性
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摘要
通过室内三轴固结排水剪切试验(CD)率定了典型剪胀性粉土的物理力学特性参数。利用有限元软件ABAQUS,建立了水平受荷下的超大直径单桩基础有限元模型,并经过了模型试验的验证。在此基础上讨论了API规范p-y曲线法对近海风机超大直径单桩的适用性;重点研究了超大直径单桩基础临界埋深影响因素。研究结果表明:API规范p-y曲线法对超大直径单桩基础难以适用;在密实度为88%的粉土地基中,无论桩径大小,Lc,const准则下的临界埋深约为8倍桩径;在进行超大直径单桩基础设计时,选取小直径大埋深的桩基尺寸组合,可大幅减少桩基重量。
Through a series of indoor triaxial compression tests(CD), we conducted to obtain physical and mechanical characteristic parameters of typical dilatancy silt, established a reasonable finite element computational model of super-large diameter monopile foundation under horizontal loading using the finite element software ABAQUS, and verified by model tests.On this basis, we discussed the applicability of API p-y curve methods to the super-large diameter monopile foundation for offshore wind turbine, and analyzed the factors affecting the critical embedded length of monopile foundation. The research results show that the widely used API p-y curve methods is not applicable to monopile foundation. No matter the size of the pile diameter, the critical embedded length of monopile under the criterion of Lc,constis about 8 times of the pile diameter in the silt with the relative density of 88%. In the design of the super-large diameter monopile foundation, the combination of small diameter and large embedded length is recommended, which can significantly reduce the pile weight.
Through a series of indoor triaxial compression tests(CD), we conducted to obtain physical and mechanical characteristic parameters of typical dilatancy silt, established a reasonable finite element computational model of super-large diameter monopile foundation under horizontal loading using the finite element software ABAQUS, and verified by model tests.On this basis, we discussed the applicability of API p-y curve methods to the super-large diameter monopile foundation for offshore wind turbine, and analyzed the factors affecting the critical embedded length of monopile foundation. The research results show that the widely used API p-y curve methods is not applicable to monopile foundation. No matter the size of the pile diameter, the critical embedded length of monopile under the criterion of Lc,constis about 8 times of the pile diameter in the silt with the relative density of 88%. In the design of the super-large diameter monopile foundation, the combination of small diameter and large embedded length is recommended, which can significantly reduce the pile weight.
引文
[1]LESNY K,WIEMANN J.Design aspects of monopiles in German offshore wind farms[C]//Proceedings of the international symposium on frontiers in offshore geotechnics.AA Balkema Publishing,2005:383-389.
[2]K UO Y S,ACHMUS M,ABDEL-RAHMAN K.Minimum embedded length of cyclic horizontally loaded monopoles[J].Journal of Geotechnical and Geoenvironmental Engineering,ASCE,2012,138(3):357-363.
[3]刘晋超,熊根,朱斌,等.砂土海床中大直径单桩水平承载与变形特性[J].岩土力学,2015,36(2):591-599.LIU Jin-chao,XIONG Gen,ZHU Bin,et al.Bearing capacity and deflection behaviors of large diameter monopile foundations in sand seabed[J].Rock and Soil Mechanics,2015,36(2):591-599.
[4]ABAQUS.User's manual[M/OL].ABAQUS Inc and DS,http://www.simulia.com/support/documentation.html.
[5]杨永垚.近海风电机组超大直径单桩承载力分析与试验研究[D].杭州:浙江大学,2012.YANG Yong-yao.Analysis and experimental study on bearing capacity of monopile for offshore wind turbines[D].Hangzhou:Zhejiang University,2012.
[6]American Petraleum Institute.Recommended practice for planning,designing and constructing fixed offshore platforms[S].21st ed.API Recommended Practice 2A-WSD(RP2A-WSD),2000.
[7]LI Y,BYRNE P M.Lateral pile response to monotonic pile head loading[J].Canadian Geotechnical Journal,2011,29(6):955-970.
[8]KIM B T,KIM N K,LEE W J,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.
[2]K UO Y S,ACHMUS M,ABDEL-RAHMAN K.Minimum embedded length of cyclic horizontally loaded monopoles[J].Journal of Geotechnical and Geoenvironmental Engineering,ASCE,2012,138(3):357-363.
[3]刘晋超,熊根,朱斌,等.砂土海床中大直径单桩水平承载与变形特性[J].岩土力学,2015,36(2):591-599.LIU Jin-chao,XIONG Gen,ZHU Bin,et al.Bearing capacity and deflection behaviors of large diameter monopile foundations in sand seabed[J].Rock and Soil Mechanics,2015,36(2):591-599.
[4]ABAQUS.User's manual[M/OL].ABAQUS Inc and DS,http://www.simulia.com/support/documentation.html.
[5]杨永垚.近海风电机组超大直径单桩承载力分析与试验研究[D].杭州:浙江大学,2012.YANG Yong-yao.Analysis and experimental study on bearing capacity of monopile for offshore wind turbines[D].Hangzhou:Zhejiang University,2012.
[6]American Petraleum Institute.Recommended practice for planning,designing and constructing fixed offshore platforms[S].21st ed.API Recommended Practice 2A-WSD(RP2A-WSD),2000.
[7]LI Y,BYRNE P M.Lateral pile response to monotonic pile head loading[J].Canadian Geotechnical Journal,2011,29(6):955-970.
[8]KIM B T,KIM N K,LEE W J,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.