砂土中吸力桶安装过程离心机试验和数值模拟研究  

Centrifuge experiment and numerical simulation of suction caisson installation in sand

作　　者：王贺 王睿[1] 张建民[1] WANG He;WANG Rui;ZHANG JianMin(Department of Hydraulic Engineering,State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学土木水利学院,水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《中国科学：技术科学》2022年第12期1792-1801,共10页Scientia Sinica(Technologica)

基　　金：国家自然科学基金(批准号:52022046,52038005)资助项目。

摘　　要：吸力桶是海洋工程中广泛使用的一种基础结构,与传统的海洋基础相比,具有成本低、安装简单和可以重复利用的优点.在安装过程中,由于负压的作用会引起土体内部超静孔压和渗流场的变化,从而显著影响吸力桶的端阻力和侧摩阻力.本研究采用离心机模型试验和任意拉格朗日-欧拉(ALE)大变形流固耦合有限元数值计算方法,探究砂土中吸力桶安装过程贯入阻力和渗流场的变化.ALE流固耦合有限元方法可以成功地模拟吸力桶吸贯安装过程,并且数值计算结果通过对比离心机模型试验得以验证.吸力桶不同安装方式之间的差异主要是由于其安装过程中产生的渗流和超静孔压引起的,因此在负压预测评价中需要采用基于流固耦合的有效应力分析以考虑渗流的重要性.Suction caissons are widely used foundations in offshore engineering.Compared with traditional forms of foundations,a significant advantage of the suction caisson is its cost-effectiveness owing to its simple installation equipment requirement,short installation time,convenience in transportation,and recycle and reuse potential.Changes in excess pore pressure and seepage field caused by penetration and suction have a significant impact on soil resistance around the caisson wall and tip.The centrifuge test and Arbitrary Lagrangian-Eulerian(ALE)large deformation solid-fluid coupled FEM are used in this study to investigate the changes in suction pressure and the seepage field during the suction caisson installation in the sand.The ALE solid-fluid coupled FEM successfully simulates suction caisson installation processes in sand observed in centrifuge tests.The difference in suction penetration resistance is found to be caused by seepage and excess pore pressure generated during suction caisson installation.Therefore,the solid-fluid effective stress analysis is needed in the evaluation of suction caisson penetration to consider the importance of seepage.

关 键 词：吸力桶安装 有限元 任意拉格朗日-欧拉方法 流固耦合 土与结构相互作用 

分 类 号：P75[天文地球—海洋科学] TU441[建筑科学—岩土工程]