【摘要】 四桶吸力式基础由4个按正方形排列的吸力式桶形基础组成,并通过上部结构连成整体共同承受外部荷载,相比于单桶基础,四桶基础能承受更恶劣的海洋环境荷载,可作为海上风机和海洋平台等结构物的基础,具有广阔的应用前景。为探究饱和软土地基上四桶基础和单桶基础在承载力以及破坏模式方面的关系,优化四桶基础的设计,建立了大量的四桶和单桶基础的三维有限元模型,系统研究了不同基础埋深和土体剪切强度时桶间距对四桶基础各单向承载能力和对应的破坏模式的影响。结果表明,竖向承载力系数受桶间距影响较小,而水平承载力系数受其影响较大,力矩承载力系数受其影响尤为显著;在同一桶间距比时,四桶吸力式基础的各单向承载力系数随基础埋深比的增加逐渐增大,随土体剪切强度不均匀度指标的增大逐渐减小。通过分析四桶基础的各单向承载力、对应的破坏模式和群效应系数,定义了四桶基础的最优桶间距,可为四桶基础桶间距的优化设计提供依据。更多还原

【Abstract】 Tetrapod bucket foundations are formed by four suction buckets into a square shape and connected by superstructure into a whole to provide better resistances against severe marine environmental loads than single bucket foundation. Tetrapod bucket foundations can serve as foundations for offshore platforms or wind turbines, and show a broad application prospect. To investigate the bearing capacities and failure mode for single and tetrapod bucket foundations, and optimizing the design of tetrapod bucket foundations, this paper established a large number of 3D finite element models of tetrapod bucket foundations in soft soil and systematically investigated the effects of bucket separation distance on uniaxial capacities and corresponding failure modes with different foundation embedment depths and soil strength heterogeneities. Results indicate that vertical capacity factors are almost independent on the bucket separation distance while horizontal capacity factors are evidently dependent on separation distance, and moment capacity factors are especially affected by separation distance. All uniaxial capacity factors of tetrapod bucket foundations increase as embedment depth increases, but decrease as soil heterogeneity index increases under the same bucket separation distance ratio. By analyzing uniaxial capacities, corresponding failure mechanisms and group effect factors of tetrapod bucket foundations, optimal bucket separation distance of tetrapod bucket foundations was defined, which can provide reference for optimizing the design of bucket separation distance of tetrapod bucket foundations.更多还原