抗拔桩荷载传递特性的积分方程解法及参数分析

Analysis for the Load Transfer Behaviors of the Uplift Single Pile with an Integral Equation Method and Parameter Studies

摘要:

针对抗拔桩的受力特点，在弹性虚拟桩模型应变协调的基础上，引入桩端受力为0的假定条件，形成第二类Fredholm积分方程组，采用最小二乘法进行求解。通过编制程序求解基本方程，得到桩身轴力、桩侧剪力和桩身位移等分布特性，与相关文献的对比表明了本文解法的正确性。文中重点分析了影响抗拔桩荷载传递特性的主要因素，如桩身刚度、桩长细比和地基土泊松比等参数。计算结果表明，桩身刚度和桩长细比对抗拔桩荷载传递特性具有显著的影响。本文解法在理论上较为严密，具有工程应用价值。

Abstract:

According to the working behavior of tension piles, the loads carried by the pile tip are assumed to be zero. A Fredholm integral equation of the second kind for single tensile pile in elastic half space is deduced based on the fictitious pile model. By solving the nonlinear equations with the least square method, the axial forces, shear forces and displacement along the pile shaft are obtained. Compared with the available literatures, the reasonable of the present method is validated. The main factors, such as the pile stiffness, the length-to-diameter ratio and the Passion’s ratio, are investigated to analyze the load transfer behaviors of the tension pile. The results showed that the pile stiffness and the length-to-diameter ratio have obvious influence on the load transfer characters of the uplift pile. Some valuable conclusions can be drawn for the theoretical analysis and engineering practices.