Abstract

In this study, the ultimate undrained bearing capacity of a laterally loaded pile, embedded in heterogeneous marine deposits exhibiting linear and bi-linear undrained shear strength profiles was calculated by putting into practice the three-dimensional finite element lower bound limit analysis in conjunction with the second-order cone programming method. The lower bound finite element bearing capacity of a laterally loaded single pile can be found by formulating the element equilibrium, discontinuity equilibrium, boundary conditions, yield function, and optimization of the objective function through these constraints by second-order cone programming method. A parametric study is also conducted to evaluate the most effective factors including the dimensionless pile embedded length ratio, soil strength parameter, heterogeneity factors, transformation depth and soil–pile interface adhesion. The findings of the current study have been compared and validated with the results reported in the literature and presented in the form of tables and figures. The results show that that the effects of heterogeneity, linear and bi-linear variations of undrained shear strength with depth are more meaningful for soft marine clay in comparison to stiff clay and the curves of heterogeneous to homogeneous bearing capacity ratio reach to the unit value by increasing the dimensionless cohesion factor.

摘要

在这项研究中，通过实施三维有限元下限分析并结合二阶锥规划法。横向荷载单桩有限元承载力的下界可以通过二阶锥规划法通过这些约束制定单元平衡、间断平衡、边界条件、屈服函数和目标函数的优化求得。还进行了参数研究，以评估最有效的因素，包括无量纲桩嵌入长度比、土壤强度参数、异质性因素、转变深度和土桩界面附着力。本研究的结果已与文献报道的结果进行了比较和验证，并以表格和数字的形式呈现。结果表明，与硬质粘土相比，不排水抗剪强度随深度的非均质性、线性和双线性变化的影响更显着，异质与均质承载力比曲线达到单位值增加无量纲内聚因子。