台风环境中海上风电管桩基础动响应特性研究

Offshore wind farms are concentrated in the southeast coastal zone of China with frequent typhoon incidents. Large-diameter open-ended monopile are the main foundation type. Under the extreme load of typhoon and wave, the dynamic response of "soil plug-monopile-surrounding soil" system affects the safe operation of offshore wind power supporting system significantly. However, existing researches are focus on the common wind and wave load. Based on the statistical analysis of the spatiotemporal characteristics of typhoon and wave load, and using the large-scale model test, CT scanning of cycle simple shear test and the "discrete-continuous" numerical simulation, the dynamic responses offshore large-diameter open-ended monopile in the typhoon environment will be investigated by incorporating the macro-scale and micro scale responses. Fully considering the spatial variability of marine soils, the macroscopic and microscopic evolutions of soil plugs, soils surrounding monopile and soil plugs-monopile-soil interface under the environment of multi-degree of freedom of cyclic load from typhoon will be explored, and a three-dimensional soil degradation model in different working conditions will be established. Based on these, the mechanism of interaction between the monopile and the complex seabed under the extreme load of typhoon will be established, and an empirical model of the accumulative deformation of monopile and natural frequency evolution will be established. The correlation between the dynamic characteristics of soil plug and surrounding soils and static penetration index will be quantified. A computational model of 3D dynamic p-y curve based on CPT-qc index will be established. These studies will provide the theoretical basis for the design and safety assessment of the monopile supported offshore wind turbines.

我国海上风电场主要分布在东南近海台风频发海域，多采用大直径敞口管桩基础。台风与极端波浪下，“土塞-管桩-桩侧土”体系的动力响应是决定支撑体系运行安全的关键因素。但现有研究主要针对常规风浪环境。本课题在统计分析台风和极端波浪荷载时空变异性基础上，采用可视化大尺度模型试验、CT扫描循环单剪试验及“离散-连续”数值仿真，宏细观相结合研究海上风电管桩在台风环境中的动力响应。充分考虑海洋土空间变异性，揭示土塞、桩侧土及土塞-管桩-桩侧土界面在台风环境多自由度循环荷载下的宏细观演变，建立针对不同工况的循环弱化三维理论模型。由此量化管桩与复杂海床在台风环境极端荷载下的相互作用机制，建立管桩累积变形和自振频率演化的理论模型。同时纳入土塞和桩侧土的动力特性与静力触探指标的关联，构建基于锥尖阻力CPT-qc的三维动力p-y曲线，为海上风机单桩支撑体系的设计与安全评估提供理论依据。

我国海上风电场主要分布在东南近海台风频发海域，且多采用大直径敞口管桩基础。“土塞-管桩-桩侧土”体系的动力响应是决定支撑体系运行安全的关键因素。对此本课题采用大型模型试验、现场试验、数值模拟和理论分析，宏细观相结合研究了海上风电管桩在台风环境中的动力响应，揭示了土塞、桩侧土及土塞-管桩-桩侧土界面在台风环境多自由度循环荷载下的宏细观演变，建立了针对不同工况的循环弱化三维理论模型，进而量化了管桩与复杂海床在台风环境极端荷载下的相互作用机制，建立了管桩累积变形和自振频率演化的理论模型，为海上风机单桩支撑体系的设计与安全评估提供理论依据。. 依托本课题先后发表论文33篇（SCI、EI检索论文21篇）；出版学术专著1部，参编国家团体标准1部；授权专利6项、实用新型11项、软件著作权22项；培养硕士研究生6人，联合培养博士1人，博士后2人；获2019年青岛市科技进步一等奖、2021年山东省科技进步二等奖，线上线下参加国际会议12次；研究成果获山东省科技进步二等奖、青岛市科技进步奖一等奖。. 依托本课题研发的近海风电“开口管桩打入方法及长期服役安全保障技术”、“桩基长期动力响应弱化机制与浅层加固防冲刷装备”等成果，由李术才院士等7位专家鉴定为“国际领先水平”，纳入我国首部近海风电国家标准《海上风力发电设计标准》、英国最权威风电手册《Wind Energy Engineering》，丰富和完善了我国近海风电设计理论与标准，扭转了我国海上风电基础设计主要参考欧美规范的被动局面。成果应用于中国离岸最远海上风电场（华能如东）、渤海湾首个风电场（唐山乐亭菩提岛）、山东首个海上风电场（三峡新能源昌邑）等多个难点工程，经济与社会效益显著。