挤扩支盘桩与钻孔灌注桩现场对比试验研究

摘要

In order to study bearing characteristics of squeezed branch piles,through the field static load tests of the squeezed branch pile and the bored pile,comparative analysis of the axial force distribution and the development of pile shaft resistance and pile toe resistance are done.Load transfer mechanism system of the branch pile and the side friction characteristics of the branches in different positions are thorough analyzed.The experiment results show that,the bearing characteristics of branch piles are stable,and its"Q-S"curves of branch piles are slow transformation.The anti-sedimentation deformation characteristics of the squeezed piles are significantly better than that of the bored piles.The side friction of the support plate plays earlier and more adequate than that of the lower branch.The bearing capacity of branch piles is about 36％ higher than that of bored piles.%为研究挤扩支盘桩的承载特性,通过挤扩支盘桩(以下简称支盘桩)与钻孔灌注桩的现场静载荷试验对比,分析试验各桩桩身轴力分布、桩侧摩阻力以及桩端阻力的发展情况,系统分析支盘桩的荷载传递机理和不同位置支盘侧摩阻力的发挥特性.试验结果表明,支盘桩的承载特性稳定,其荷载-沉降曲线均为典型的缓变形,抗沉降变形特性明显优于钻孔灌注桩;上支盘侧摩阻力比下支盘发挥的早且充分;支盘桩极限承载力较钻孔灌注桩高出36％左右.