上海超长桩荷载传递函数实测分析和数值模拟

Field analysis and numerical simulation on load transfer function of super-long pile in Shanghai

结合虹桥交通枢纽和上海中心大厦工程试桩资料,探讨上海地区超长桩试桩侧摩阻力随桩侧土体剪切位移的变化规律,并归纳为线弹性、理想弹塑性、加工硬化和加工软化四类荷载传递曲线。在此基础上,将实测荷载传递曲线概化为非加工软化型和加工软化型,分别建立相应的侧摩阻力荷载传递函数的理论表达式和参数经验值,同时与现场实测数据进行对比分析。利用矩阵位移法自编软件,基于实测荷载传递函数,对上海地区超长桩的荷载传递基本微分方程进行数值求解,可理想模拟单桩承载特性,但单桩刚度略高于实测成果。

According to the pile test information of super-long piles in Hongqiao Transportation Hub and Shanghai Tower project, the mechanism of shaft resistance with shear displacement of pile shaft soil was proposed in Shanghai region, and four kinds of load transfer curves as to linear elasticity, ideal elastic-plasticity, work hardening and work softening were summarized. On this basis, the load transfer curves are generalized to the non-work-softening and work-softening, the theoretical expressions and parameter values of the load transfer function of the shaft resistance are established respectively, and the calculated results are compared with the measured data. Based on the measured load transfer function, the basic differential equation of load transfer of super long piles in Shanghai region is numerically solved in which the procedures has been compiled using the matrix displacement method. The analysis shows that the bearing capacity of single pile can be simulated well, but the stiffness of single pile is slightly higher than the measured result.