考虑超长桩桩周土体加工软化和加工硬化等不同性状,采用三折线荷载传递模型模拟其竖向荷载下桩侧传递规律,并以理论τ-z曲线描述桩侧界面桩土接触非线性。在此基础上,针对荷载传递过程中桩土滑移现象,对超长桩及桩周土分别建立单元进行离散化处理,根据桩土体系平衡条件得出桩土体系刚度矩阵方程及其迭代求解流程,从而提出了可考虑桩土滑移的超长桩沉降计算非线性分析算法.与现场试桩实测数据对比表明,本文方法计算值与实测值基本吻合,可供工程实践参考。
A simplified approach was proposed to calculate the settlement of super-long pile subjected to vertical load. Firstly, a three-line model of load transferring was developed to simulate the transferring law of super-long pile considering the work hardening or work softening characteristics of the soil around the pile, and the theory of r-z curve was also used to describe the nonlinear characteristics of the contact inter- face between pile and soil. Then, considering the relative slide, the pile and the soil were discret to estab- lish units respectively, so the stiffness matrix equation and the method of iteration were also deduced ac- cording to the equilibrium conditions of the pile-soil system. Therefore, the method for the evaluation of the settlement of super-long pile considering the relative slide between pile and soil was proposed. Finally, the theoretical calculation was compared with the field test, and a good agreement has been obtained, which means that the calculation method can provide a reference to engineering practice.