海上风电大直径单桩基础循环重固结效应离心机试验研究  

Centrifuge tests on effects of episodic cycling and reconsolidation on large-diameter monopile foundations for offshore wind turbines

作　　者：赖踊卿 李炜 戚海峰 何奔 王欢 LAI Yong-qing;LI Wei;QI Hai-feng;HE Ben;WANG Huan(PowerChina Huadong Engineering Corporation Limited,Hangzhou,Zhejiang 310058,China;The Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China;Norwegian Geotechnical Institute,Oslo 0855,Norway)

机构地区：[1]中国电建集团华东勘测设计研究院有限公司,浙江杭州310058 [2]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124 [3]挪威岩土工程研究所,挪威奥斯陆0855

出　　处：《岩土力学》2024年第10期2994-3002,3012,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52301343);浙江省自然科学基金(No.LQ23E090003);中国博士后科学基金(No.2022M722960);浙江省博士后科研择优资助项目(No.ZJ2022001)。

摘　　要：我国东南沿海台风频发,海上风机在其服役期内往往经历多次循环重固结阶段。然而当前绝大多数研究仅局限于未经历重固结的单桩循环响应,鲜有研究考虑循环重固结效应对后续单桩响应的影响。为此,针对软黏土中两种桩径的大直径单桩基础开展了一系列不同幅值下的循环重固结离心机试验,旨在揭示并量化循环重固结效应对大直径单桩循环累积位移、桩头刚度等关键设计指标的影响。试验结果表明:同等循环荷载幅值下,经历2轮循环重固结后,单桩基础桩头刚度相比初始刚度最大提高了1.5倍,这使得单桩累积位移显著减小,最大减幅达63%。因此,若设计过程中不考虑循环重固结效应对单桩后续循环响应的影响,而直接将每场极端台风下单桩的累积位移进行累加,则会严重高估桩头累积位移,使单桩基础设计偏于保守。Typhoons frequently occur along the southeastern coast of China,and offshore wind turbines often suffer from multiple cycling and reconsolidation during their service life.However,there is currently limited research on effects of cycling and reconsolidation.To address this,a series of centrifuge tests was conducted on two types of large-diameter monopile foundations in soft clay with different amplitudes,aiming to reveal and quantify the impact of episodic cycling and reconsolidation effect on key design indicators such as cumulative displacement and pile head stiffness of large-diameter monopiles.The test results show that under the same cyclic load amplitude,after two episodes of cycling and reconsolidation,the maximum stiffness of the pile head of monopile foundation can increase by 1.5 times compared to the initial stiffness.This significantly reduces the cumulative displacement of the monopile,with a maximum reduction of 63%.Therefore,if the episodic cycling and reconsolidation effect on the subsequent cyclic response of a monopile is not considered in the design process,and the cumulative displacement of a monopile under each extreme typhoon is directly accumulated,it will seriously overestimate the cumulative displacement of the pile,leading to a conservative design.

关 键 词：海上风机 大直径单桩 循环重固结效应 离心机模型试验 

分 类 号：TU473[建筑科学—结构工程]