考虑外平台影响下海上风机单桩基础结构地震动力响应分析

Seismic Dynamic Response Analysis of Offshore Wind Turbine Single-pile Foundation Structure Considering the Influence of External Platform

随着海上风机单桩基础的广泛应用,分析单桩基础及其附属结构在地震荷载作用下的动力响应具有重要意义。为此,采用ABAQUS有限元分析软件建立了单桩-外平台整体结构模型,采用粘弹性边界法模拟地震荷载施加,分析了地震作用下整体结构的动力响应情况,并探究了外平台对单桩自振特性及响应的影响。研究结果表明:地震荷载作用下,单桩-外平台整体结构的应力最大值出现在工作平台和支撑杆连接处,水平位移最大值出现在顶部工作平台上,牛腿应力和位移相对较小;外平台对单桩的自振频率具有减缓增大的作用,可降低基频,且会小幅度增大单桩基础应力,对单桩基础的稳定工作不会产生较大影响。

With the wide application of single-pile foundation for offshore wind turbines,it is important to analyze the dynamic response of single-pile foundation and its affiliated structures under earthquake load.In this paper,by using the ABAQUS finite element analysis software to establish the whole structure model of single pile-external platform and the viscoelastic boundary method to simulate the earthquake load,the dynamic response of whole structure under earthquake is analyzed,and the influences of external platform on the natural vibration characteristics and response of single pile are also explored.The results show that,(a)under the earthquake load,the maximum stress of overall single pile-external platform structure appears at the joints between the working platform and the supporting bars,the maximum horizontal displacement appears at the working platform,and the stress and displacement of the bracket are relatively smaller;and(b)the external platform can slow down and increase the natural frequency of single-pile foundation,reduce the fundamental frequency,and slightly increase the stress of single-pile foundation,but its influence on horizontal displacement is not significant.