STUDY ON HORIZONTAL BEARING CAPACITY OF SUCTION BUCKET FOUNDATION FOR OFFSHORE WIND POWER IN SOIL
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摘要: 砂性土地基中海上风机吸力桶基础水平承载特性对海上风机稳定性至关重要。本文通过室内模型试验,对不同荷载循环比作用下砂性土地基吸力桶基础水平承载特性进行了研究。试验表明:当循环荷载比ζb=0.33时,吸力桶基础累积变形在循环过程中变化不大; 当循环荷载比ζb=1.0时,吸力桶基础累积变形随循环次数增加一直增大并且有继续增大的趋势,循环结束后,ζb=0.33及ζb=1.0的循环累积变形分别为0.006D、0.149D。在ζb=0.33及ζb=1.0的水平循环荷载作用下,50次循环结束后累积旋转角度分别为不同循环荷载比作用下第1次循环累积转角的1.43倍和1.76倍,随着循环次数增加,旋转中心的位置逐渐向上移动,最终稳定在砂面以下0.8L处左右。研究结果可为砂性土地基海上风机吸力桶基础的设计与施工提供理论依据。Abstract: Compared with pile foundation,suction caisson has the advantages of convenient construction and recyclability,and is more suitable for deep sea area. Horizontal cyclic response is important for the stability analysis of suction caisson as it suffers the long-term wave loads in service period. This paper presents the results of a series of 1g model tests under horizontal cyclic loading in sand. The cumulative deformation,rotation angle and rotation center of model caisson are discussed in detail. Test results indicates that the horizontal displacement of model caisson in sand accumulates with increase of cyclic numbers and horizontal loading. Under the horizontal cyclic loads of ζb=0.33 and 1.0,the change rule of bucket caisson rotation angle and rotation center is consistent with the cumulative deformation. After 50 cycles,the cumulative rotation angle is 1.43 times and 1.76 times of the first cycle under different cyclic load ratios. With the increase of the number of cycles,the position of the rotation center gradually moves upward,and finally stabilized at about 0.8L below the sand surface. This study can provide theoretical basis for the design of suction caisson as offshore wind power foundation in sand.
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Key words:
- Sand /
- Suction caisson /
- Horizontal circulation /
- Cumulative deformation /
- Center of rotation
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表 1 土粒试样物理力学参数
Table 1. Mechanical parameters of sand
物理参数 平均粒径d50/mm 最小干密度ρd,min /g·cm-3 最大干密度ρd,max /g·cm-3 相对密度Dr 内摩擦角φ /(°) 重度γ /kN·m-3 量值 0.71 1.37 1.72 51.39% 34 20 -
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