基于FLAC 3D有限差分软件平台,利用SANISAND本构模型模拟砂土的应力应变行为,系统研究局部冲刷条件下竖向拉伸荷载和地震荷载共同作用时吸力桶基础的动力行为。研究发现地震作用会使得竖向受拉的吸力桶基础产生累积竖向位移,进而可能导致基础因累积位移过大而失效破坏,且冲刷会增加地震作用下砂土液化区域的深度,使得桶-土摩阻力降低,导致吸力桶的抗拔承载力降低,加剧基础破坏发生。在水平方向距离吸力桶外壁越近砂土液化程度越弱,且吸力桶内部累积孔压明显小于吸力桶外部,表明吸力桶的存在对周围砂土的液化有显著的抑制作用。
Abstract
This study leverages the FLAC 3D finite difference software platform and utilizes the SANISAND constitutive model to simulate the stress-strain behavior of sand soil. It systematically investigates the dynamic behavior of suction bucket foundations under the combined action of vertical tensile loads and seismic loads in the context of local scour conditions. The findings reveal that seismic actions can induce cumulative vertical displacement in suction buckets subjected to vertical tensile loads, potentially leading to foundation failure due to excessive displacement. Scour exacerbates this issue by increasing the depth of liquefied sand under seismic loading, reducing the bucket-soil frictional resistance, and diminishing the uplift capacity of the suction bucket, thereby further compromising the foundation's integrity. Additionally, the degree of liquefaction in the surrounding sand decreases with decreasing distance from the outer wall of the suction bucket in the horizontal direction. Notably, the cumulative pore pressure inside the suction bucket is significantly lower than that outside, indicating that the presence of the suction bucket exerts a substantial inhibitory effect on the liquefaction of the surrounding sand.
关键词
海上风电 /
液化 /
冲刷 /
吸力桶基础 /
地震荷载 /
张拉荷载
Key words
offshore wind power /
liquefaction /
scour /
suction bucket foundation /
earthquake loads /
tensile load
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基金
国家自然科学基金（52378361）; 天津市自然科学基金（22JCYBJC01360）
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