Bearing capacity of composite bucket foundations for offshore wind turbines in silty sand
Bearing capacity of composite bucket foundations for offshore wind turbines in silty sand
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DOI：
10.1016/j.oceaneng.2018.01.006
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发表时间：
2018-03
影响因子：
5
通讯作者：
Nan Jia;Puyang Zhang;Yonggang Liu;H. Ding
中科院分区：
文献类型：
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作者：
Nan Jia;Puyang Zhang;Yonggang Liu;H. Ding
七格蜂窝结构复合筒型基础是一种新型的海上风力发电机组结构形式。在江苏沿海一个水深0.4m的饱和粉砂天然水池中进行了现场试验，以评估CBF的水平承载力。不同加载步长下土压力沿着筒裙的分布有助于解释筒裙变形引起的土-筒相互作用。结果表明，荷载的增加将导致斗裙外被动区的土压力显著增加，而相应主动区的裙壁上的土压力基本保持不变。此外，在斗盖与土壤之间的分离内部的吸力导致在更大的加载应用的潜在承载力，虽然它将随着进一步的位移而消散，因为在粉砂中观察到渗流。当有限元模型中土体的弹性模量约为室内试验所得压缩模量的4 ~ 5倍时，有限元模拟得到的荷载-位移关系与试验结果基本一致。根据试验和有限元计算结果，在极限水平荷载作用下，沿荷载方向，CBF的转动中心约为舱壁周围土壤表面以下沿着0.8裙高。
A composite bucket foundation (CBF) with seven compartments arranged in a similar honeycomb structure is a relatively new type of structure for offshore wind turbines. Field tests were conducted at a natural water pool with a water depth of 0.4 m in saturated silty sand off the coast of Jiangsu to estimate the horizontal bearing capacity of the CBF. The distribution of soil pressures along the skirt of the CBF with different loading steps helps in explaining the soil-bucket interaction due to the deformation of the CBF. The results show that an increased load will result in a significant increase in the soil pressure in passive zones outside the bucket skirt whereas the soil pressure on the skirt wall in the corresponding active zone remains largely the same. Moreover, the suction pressure inside the separation between the bucket lid and the soil results in a potential bearing capacity with larger loading application, though it will dissipate with further displacement because seepage is observed in the silty sand. The load-displacement relationships obtained using a FEM simulation are almost in same trend with the test results when the elasticity modulus of the soils in the FEM model is set approximately four or five times the compression modulus obtained from the laboratory test. The rotation center of the CBF obtained from the test and FEM results is approximately 0.8 skirt height below the soil surface around the bulkhead along the loading direction under the ultimate horizontal loading.