| 摘要: |
| 采用有限元法，建立超长桩和土体共同作用的三维数值模型，研究受边载和水平荷载共同作用下超长桩的承载特性，分析超长桩侧摩阻力和桩身弯矩的变化规律。结果表明：水平荷载与边载比值k的增大可以有效改善桩侧负摩阻力，并且存在最优比值k=4。桩侧负摩阻力和桩身弯矩随着长径比的减小而减小；存在临界边载距离s=8 m，当边载距离s<8 m时，桩身负摩阻力随着边载距离的增大而减小，当s＞8 m时，边载对桩身负摩阻力几乎无影响。桩土刚度比的减小可有效提高超长桩承载力。同时应用多元非线性回归分析，得到最小桩侧摩阻力随不同因素变化的函数关系式。根据该式可预测不同因素组合下的最小桩侧摩阻力，有效避免桩侧负摩阻力的产生。 |
| 关键词: 超长桩 边载 水平荷载 侧摩阻力 桩土刚度比 多元非线性回归分析 |
| DOI： |
| 分类号:TU473 |
| 基金项目: |
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| Numerical analysis of bearing capacity of super long pile subjected to side and lateral loads |
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LIN Xiao-cheng, YAO Wen-juan
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Department of Civil Engineering, Shanghai University, Shanghai
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| Abstract: |
| A three-dimensional numerical model for pile-soil interaction is established, based on studies of the bearing capacity of a super long pile under side and lateral loads. And the varying law of skin friction and moment of the super long pile is analyzed. The analysis results show that the increasing of the ratio k of the lateral load and the side load is effective in reducing the negative skin friction; furthermore, the critical ratio k is 4. The negative skin friction and moment decrease as a result of length-diameter ratio decrease. Moreover, the critical side load distance s is 8 m. When s <8 m, the negative skin friction decreases as a result of increase of s. When s >8 m,it almost has no effect on the negative skin friction. The bearing capacity of the super long pile can be effectively improved by decrease of stiffness ratio of the pile and soil. Meanwhile, by using multivariate nonlinear regression analysis, the expressions of the minimum skin friction on different factors are achieved. Then the minimum skin friction with different combinations of factors can be predicted by the expression. Thus the negative skin friction can be avoided effectively. |
| Key words: super long pile side load lateral load skin friction stiffness ratio of pile and soil multivariate nonlinear regression analysis |
