均质软黏土中双筒吸力桩基础最佳荷载作用点不排水承载特性数值分析

Numerical Study on Undrained Uplift Bearing Capacity of Optimal Loading Point of Double-bucket Suction Pile Foundation in Homogeneous Soft Clay

基于通用静力总应力分析方法,利用有限元软件ABAQUS建立了双筒吸力桩基础的三维有限元承载力模型,提出两种最佳荷载作用点判别标准,确定双筒基础受荷时最佳加载点位置随筒间距和加载角度的变化规律.对最佳荷载作用点作用下,不同长径比、不同筒间距、不同加载角度对双筒基础受荷的破坏模式和失稳机理进行分析,得到了承载力V-H破坏包络线.本研究总结归纳双筒基础极限破坏位移的发展规律,提出了判断双筒基础达到极限承载力的位移标准.通过与单筒基础最佳荷载作用点受荷相比,得到双筒吸力桩基础不同加载角度受荷的群桩效应系数,为海底工程设施的基础设计提供可借鉴依据.

In this paper,based on the general static total stress analysis method,the finite element software ABAQUS is used to establish a three-dimensional finite element model of the double-bucket suction pile foundation.Two criteria for determining the optimal loading point are proposed,and the law of the optimal loading point position changing with the suction bucket foundation spacing and loading angle is determined.Under the optimal loading point,the failure mode and instability mechanism of the double bucket foundation under loading with different length-todiameter ratios,different bucket spacings,and different loading angles are analyzed and discussed,and the V-H failure envelope is obtained.The development law of the ultimate failure displacement of the double-bucket foundation is summarized,and the displacement standard for judging the ultimate bearing capacity of the double-bucket foundation is put forward.Compared with the load of the optimal loading point of the single bucket foundation,the group bucket pile effect coefficient of the double-bucket suction pile foundation under different loading angles loaded is obtained,which can provide a reference for the foundation design of submarine facilities.