扩顶CFG桩的沉降和应力研究

Research on the sedimentation and stresses of belled CFG pile

从理论上分析了扩顶CFG桩的作用机理,以辽宁某石油储罐工程为背景对桩体的力学性能进行了分析,并运用FLAC3D有限差分程序进行了计算机模拟,对普通柱桩和扩顶桩从桩土沉降差、桩土应力比和桩身轴力3个方面进行了对比分析,同时得出了扩顶桩的桩侧摩阻力的分布图。对比表明扩顶CFG桩在不改变桩身直径的前提下能较大的减少桩土沉降差和增大桩土应力比,桩顶起到了很好的“荷载收集”作用,有效的提高桩体承受的荷载和桩土应力比,充分发挥高承载力桩的特性。

In this paper, the theoretical action mechanism of the extended-tip CFG pile and the mechanic capability of the pile based on an oil tank project in Liaoning are analyzed successively, simulative calculation with the finite differential program FLAC3D is progressed to compare the pile-soil differential settlement, the pile-soil stress ratio and the axial force of pile shaft between ordinary column pile and extended-tip pile respectively. The results show the distribution of the side friction resistance of the extended-tlp pile and the comparison indicates that the extended-tip CFG pile can decrease the pile-soll differential settlement and increase the pile-soil stress ratio greatly without changing the diameter of the pile. The pile tip which has good function of ＂ load collection＂ enhances the bearing capacity of the pile and the pile-oil stress ratio to represent the characteristic of high bearing capacity pile fully.