苏通大桥主塔墩基础群桩效应研究

Pile group effect of main pylon foundation of Sutong Bridge

在苏通大桥主塔墩群桩基础与土体共同作用三维非线性有限元方法分析的基础上,研究了群桩效应对高桩承台底面受力与变形特性、基桩轴力分布、桩侧摩阻力、桩底土附加应力的影响以及桩数变化对群桩效率系数的影响,拟合得出了苏通大桥基桩轴力和群桩效率系数的计算方法.结果表明,在桩径和桩距一定的条件下,群桩效率系数的变化幅度随桩数的增加逐渐减小,并最终趋于定值.

Based on 3D nonlinear FEM analysis of the interaction between pile group foundation of main pylon of the Sutong Bridge and soil, the influences of pile group effect on the stress and deformation of bottom sm＇face of high-rise pile cap, axial force distribution of piles, friction along piles, and additional stress in soil under piles, and the influence of variation of pile number on the coefficient of pile group efficiency were investigated. The calculation methods for axial force of foundation piles and the coefficient of pile group efficiency were obtained by numerical simulation. The result of study shows that, for piles with certain diameter and span, the variation of the coefficient of pile group efficiency decreases as the number of piles increases, and finally reaches a certain value.