考虑桩土界面相对位移与界面外土体剪切变形抗拔桩荷载传递分析

Load Transfer Analysis of the Tension Pile Considering the Relative Displacement of Pile-Soil Interface and Shear Deformation of Soil Outside Interface

传统理论分析方法在分析桩体荷载位移关系时,都存在各自不同的缺陷。剪切位移法假定桩土界面不产生相对滑移,荷载传递法的分析计算是基于一种表征桩侧摩阻力与桩体总位移关系的桩土荷载传递模型之上,但事实上桩侧摩阻力是由桩土界面相对滑移产生的。通过对抗拔桩变形模式进行分析发现,桩体总位移可以分为桩土界面相对位移与桩土界面外土体位移两部分。因此,通过建立一种表征桩侧摩阻力与桩土界面相对位移关系的桩土界面荷载传递模型,结合使用桩土界面荷载传递原理与剪切位移法对两部分位移量进行计算,从而得到了不同荷载作用下桩体总位移。通过与工程实例进行对比,证明了本方法的合理性。

The traditional theoretical analysis method has different defects in the analysis of pile displacement. The shear displacement method assumes that the pile-soil interface does not produce relative slip. And the analysis of the load transfer method is based on a pile-soil load transfer model that characterizes the relationship between pile-side friction and the absolute displacement of the pile-soil. But in fact,the pile side friction is caused by the relative slip of the pile-soil interface. The author analyzes the deformation model of the pile,and finds that the displacement of pile at any position can be partitioned to the relative displacement on pile-soil interface and the displacement of surrounding soils. Therefore,this paper establishes a pile-soil interface load transfer model that characterizes the relative displacement relationship between friction and pile-soil interface. The displacement of the two parts is calculated by using the pile-soil interface load transfer principle and the shear displacement method,and the total displacement of the pile under different loads is obtained. The applicability and accuracy of this method was examined on an practical example.