基于载荷试验的超长桩应力传递机理分析

摘要

This paper uses the Boltzmann model to fit a load transferring function between pile soil and pile endpoint soil during a number of superlong pile load tests undertaken in Shanghai. The results of these tests were analyzed to determine the mechanisms whereby loads are transferred within superlong piles using a finite beam element method and a load transfer function. The results show that fitting of Boltzmann load transfer function to experimental results is a useful and accurate approach to simulate the single pile Q-S curve and frictional resistance. The near-perfect elastic–plastic function relationship between the lateral friction of the pile, the relative displacement of the pile soil, and the nonlinear behavior of the pile concrete material means that the results of simulated single pile Q-S curves and field tests diverge.%　　基于上海某工程超长桩载荷试验成果，采用Boltzmann数学模型拟合了桩侧土和桩端土的荷载传递函数，进而采用有限杆单元法和荷载传函数分析了单桩荷载传递机理。结果显示，基于试桩成果拟合得到的Boltzmann荷载传递函数，可以较好的用于模拟单桩Q-S曲线及侧摩阻力发挥过程，由于桩侧摩阻力与桩土相对位移接近理想弹塑性的函数关系、桩身材料的非线性等因素，会导致模拟的单桩Q-S曲线与实测结果存在差异。