考虑混凝土损伤和钢筋屈服的海上单桩基础水平承载特性数值分析

发布时间：2019-05-01 06:11

【摘要】：采用三维非线性有限元方法对水平荷载作用下海上单桩基础力学响应进行了比较系统的数值分析.桩身混凝土采用弥散开裂模型,钢筋采用基于Mises屈服准则的理想弹塑性本构模型.首先对已有的基桩水平静载原位试验进行了数值模拟,计算结果与相关试验数据比较吻合.进而探讨桩周土内摩擦角、变形模量、桩体配筋率及竖向荷载水平等对海上单桩桩头水平位移与水平承载力的影响,结果表明:增大桩周土内摩擦角可有效提高桩基水平承载力.配筋率较低的单桩,其水平承载力容许值主要受桩身开裂控制,而对于配筋率较高的桩,水平承载力容许值受桩头水平位移控制.由上部结构物传递下来的竖向荷载有利于桩顶侧移的减小,但同时会增加桩身最大弯矩,最优竖向荷载水平为单桩竖向极限荷载的0.4~0.6倍.
[Abstract]:A three-dimensional nonlinear finite element method is used to analyze the mechanical response of offshore single pile foundation under horizontal load. The dispersion cracking model is used for pile concrete and the ideal elastoplastic constitutive model based on Mises yield criterion is used for reinforcing steel bar. First, the numerical simulation of the existing horizontal static loading test of pile is carried out, and the calculated results are in good agreement with the related experimental data. Furthermore, the effects of internal friction angle, deformation modulus, reinforcement ratio and vertical load level on horizontal displacement and horizontal bearing capacity of offshore single pile head are discussed. The results show that the horizontal bearing capacity of pile foundation can be improved effectively by increasing the internal friction angle of soil around the pile. For the single pile with lower reinforcement ratio, the allowable value of horizontal bearing capacity is mainly controlled by the crack of the pile body, while for the pile with higher reinforcement ratio, the allowable value of horizontal bearing capacity is controlled by the horizontal displacement of the pile head. The vertical load transmitted by the superstructure is beneficial to the reduction of the lateral displacement of the pile top, but it also increases the maximum bending moment of the pile body. The optimal vertical load level is 0.4 脳 0.6 times of the vertical limit load of a single pile.
【作者单位】：鲁东大学岩土工程重点实验室;河海大学土木与交通学院;
【基金】：国家自然科学基金项目(50909048) 山东省自然科学基金项目(ZR2015EM047) 中国博士后科学基金项目(2015M581713)
【分类号】：U443.15

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