Research on the Mechanical Properties and Reinforcement Approach for Cold Joints in Onshore Wind Turbine Spread Foundations
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摘要: 扩展式基础是陆上风机最常用的现浇基础形式,其混凝土一次浇筑量大。由于建设场地交通不便或恶劣天气状况的影响,基础浇筑过程中可能会因中断浇筑而产生施工冷缝。以5 MW风机基础为对象,研究施工冷缝对结构性能的影响。针对底板、圆台、台柱三个典型冷缝位置,建立精细化有限元模型。以无冷缝基础为对照,分析了极端工况下三种冷缝位置基础的整体性能及界面受力情况,验算了疲劳工况下基础混凝土和钢筋的疲劳寿命,给出了施工冷缝界面的加固方案。结果表明:对比无冷缝的风机基础,带冷缝基础混凝土压应力有所提升,但仍处于安全范围;通过疲劳验算发现施工冷缝处混凝土与钢筋均能满足20年使用寿命;对于底板冷缝,冷缝界面滑移超过弹性限值,采取加固措施后,界面滑移能够保持在弹性安全范围内,加固方案具有良好效果。Abstract: The spread foundation is the most commonly used cast-in-place foundation type for onshore wind turbines, requiring a large volume of concrete to be poured at one time. Due to factors such as limited site accessibility or adverse weather conditions, construction cold joints may occur during the foundation pouring process as a result of interruptions. Considering that the existence of construction cold joints may have an adverse effect on the safety performance of the wind turbine foundation, this paper takes a 5 MW wind turbine spread foundation as an example and analyzes the mechanical properties of the foundation with construction cold joints. Cold joints are considered at locations such as the base slabs, truncated cones, and columns. A refined finite element model of the wind turbine foundation with and without cold joints was established. The overall performance and interfacial stress conditions of the foundation with and without cold joints were analyzed under extreme conditions, and the fatigue life of the concrete and rebars in the foundation was verified under fatigue conditions. A reinforcement approach was applied for the cold joint interface. The results showed that, compared to the foundation without cold joints, the compressive stress in the concrete of the foundation with cold joints increased but remained within the safe range. Fatigue verification demonstrated that both the concrete and rebars in the foundation with cold joints could meet the 20-year service life requirement. For the base slab cold joints, the slip displacement at the interface exceeded the elastic limit; however, after implementing reinforcement measures, the interfacial slip displacement was maintained within the elastic stage, proving the effectiveness of the approach.
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[1] 张伯泉,杨宜民. 风力和太阳能光伏发电现状及发展趋势[J]. 中国电力,2006(6):65-69. [2] 吴丰林,方创琳. 中国风能资源价值评估与开发阶段划分研究[J]. 自然资源学报,2009,24(8):1412-1421. [3] GWEC. GWEC global wind report 2024[R]. Brussels:Global Wind Energy Council,2024. [4] 国家能源局. 陆上风电场工程风电机组基础设计规范:NB/T 10311—2019[S]. 北京:中国水利水电出版社,2020. [5] 王胜利. 混凝土施工冷缝预防及处理措施[J/OL]. 城市建设理论研究(电子版),2013(24)[ 2013-10-19]. https://d.wanfangdata.com.cn/periodical/CiBQZXJpb2RpY2FsQ0hJU29scjkyMDI2MDMwNjE2NTI1NxIRY3Nqc2xseWoyMDEzMjQzOTgaCHgzOG41MW5o. [6] 黄昊,吕小彬,李萌,等. 风机混凝土扩展基础施工冷缝缺陷检测与评估技术[J]. 中国水利水电科学研究院学报,2013,11(3):232-235. [7] 宋英龙,孙文,胡斌. 不同位置施工冷缝对风机基础力学性能影响的研究[J]. 电力勘测设计,2024(10):52-57. [8] 吕仁帅,张艳丽,章荣国,等. 风电机组基础施工过程中的冷缝处理措施分析[J]. 风能,2013(5):88-91. [9] Dassault Systemes Simulia Corporation. ABAQUS/standard user’s manual[M]. Providence,RI:Dassault Systemes Simulia Corp,2014. [10] 荀永宁,冯泽慧. 柱帽处施工冷缝对无梁楼盖承载安全性影响的数值模拟分析[J]. 江苏建筑,2019(6):67-71. [11] 陈峰,郑建岚. 自密实混凝土与老混凝土粘结滑移关系的有限元分析[J]. 武汉大学学报(工学版),2014,47(6):774-778. [12] 刘健. 新老混凝土粘结的力学性能研究[D]. 大连:大连理工大学,2000. [13] 周剑. 预制混凝土空心模剪力墙应用技术研究[D]. 北京:清华大学,2015. [14] 王少波. 新老混凝土粘结面抗剪强度实验研究[D]. 郑州:郑州大学,2000. [15] British Standards Institution. Eurocode 2:design of concrete structures-part1:general rules and rules for buildings:DD ENV 1992-1-1[S]. London:British Standards Institution,1992. [16] 吕伟荣,何潇锟,卢倍嵘,等. 插环式风机基础疲劳损伤机理研究[J]. 建筑结构学报,2018,39(9):140-148. [17] Germanisher Lloyd Industril Services GmbH. Guideline for the certification of wind turbine[S]. Hamburg:Germanisher Lloyd Industril Services GmbH,2010. [18] Ifédération International Du BéTon. Model code 2010—first complete draft:volume 2[S]. Lausanne:International Federation for Structural Concrete,2010. [19] 王振扬. 基础环式风机基础动力响应特性与疲劳破坏加固方法研究[D]. 武汉:武汉大学,2022. [20] 张雷顺,王二花,闫国新. 植筋法新老混凝土粘结面剪切性能试验研究[J]. 郑州大学学报(工学版),2006(3):34-37. -
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