【作者】 冯航； 时振昊； 黄茂松； 沈侃敏； 王滨；

【Author】 FENG Hang;SHI Zhen-hao;HUANG Mao-song;SHEN Kan-min;WANG Bin;Department of Geotechnical Engineering,Tongji University;Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University;PowerChina Huadong Engineering Corporation Limited;

【机构】 同济大学地下建筑与工程系； 同济大学岩土及地下工程教育部重点实验室； 中国电建集团华东勘测设计研究院有限公司；

【摘要】 吸力桶抗拔承载特性是海上风电导管架吸力基础抵抗倾覆荷载的关键。底部反向承载力是不排水条件下吸力基础竖向极限抗力的主导部分。利用有限元数值模拟,通过自定义接触面模型分离底部反向承载力和基础侧摩阻力,重点研究了地基强度非均质性、土桶接触面粗糙程度、基础长径比对吸力桶底部反向承载力的影响,基于剪切塑性区分析了不同工况下吸力桶底部承载破坏机理。主要结论包括:(1)强度非均质性和土桶界面粗糙程度的增长可导致底部反向承载力系数的提高;(2)强度非均质性较小时,反向承载力系数随基础长径比单调递增,非均质性较大时,承载力系数随长径比的提高呈先减小再增大趋势,承载力系数变化规律与基础底部土中塑性区发展具有较好对应关系。更多还原

【Abstract】 The uplift response of suction caisson is vital for the ability of suction caisson jacket to resist overturning moment.Reverse end-bearing capacity is the predominant component of tensile capacity of suction caisson under undrained conditions.Based on user-defined soil-structure interface,a finite element model(FEM) is constructed that allows isolating reverse end-bearing capacity from total foundation tensile capacity.By using the FEM,this study investigates the influences of the non-homogeneity of soil strength,roughness of soil-caisson interface,and the length-over-diameter ratio on the reverse bearing capacity of suction caisson.The failure mechanism related to reverse end-bearing is explored by analyzing the distribution of soil shear plastic strains.The main conclusions include:(1) The increase in the non-homogeneity of soil strength and the roughness of soil-caisson interface can enhance reverse end-bearing capacity factor;(2) Reverse end-bearing capacity factor rises monotonically with length-over-diameter ratio when the soil strength non-homogeneity is relatively small,whereas first decreases then increases when the strength non-homogeneity becomes stronger,correlated well with the variation in the size of plastic shear zone.更多还原