新型海上风电基础地基冲刷深度试验研究及床面剪切力分析

Experimental investigation of scour depth and bed shear force of new offshore wind power foundation

海洋环境作用下海上风电基础周围海床会产生显著冲刷,冲刷深度过大会严重影响风电结构体系的安全。复合筒型基础是一种新型的浅基础,其对冲刷的敏感性更大。以新型的海上风电复合筒型基础为研究对象,开展了波流作用下基础周围地基冲刷特征的物理模型试验,探究了基础周围海床的冲刷变化规律及最大冲刷深度,基于波流-复合筒型基础-地基相互作用的数值模型分析了海床表面剪切力的分布特征,考察了最大冲刷深度与最大床面剪切力的关联性。研究结果表明:波流作用下复合筒型基础最大冲刷位置位于基础后方、毗邻基础的位置,最大冲刷深度随波高、周期、流速的减小而减小,基础周围海床最大冲刷深度与其最大床面剪切应力的分布有一定的相关关系。

Under the action of ocean environment,significant scour will occur around the seabed of offshore wind turbine foundations.If the scour depth is too large,it will seriously affect the safety of the wind turbine structure system.The composite bucket foundation is a new type of shallow foundation,which is more sensitive to scour.Taking the new offshore wind power composite bucket foundation as the research object,a physical model experiment of the foundation's surrounding scour characteristics under wave and current action was carried out.The scour variation characteristics and maximum scour depth of the seabed around the foundation was investigated.Based on the numerical model of wave-current with composite bucket foundation and soil,the distribution characteristics of bed shear force on the seabed surface were analyzed,and the correlation between the maximum scour depth and bed shear force was examined.The research results show that under the action of waves and currents,the maximum scour depth of the composite bucket foundation is located behind the foundation and adjacent to the foundation.The maximum scour depth decreases with the decrease of wave height,period,and flow velocity.The maximum scour depth of the seabed around the foundation has a certain correlation with the distribution of its maximum bed shear stress.