DX旋挖挤扩灌注桩单桩抗拔承载性状的数值分析

Numerical analysis on uplift bearing characteristic of cast-in-situ DX pile

总结了DX桩的抗拔研究现状,采用FLAC3D对具有两个承力盘的DX单桩和相同直径与长度的普通直孔桩做了抗拔的数值计算分析,对DX单桩抗拔的性状进行了研究。模型参数依据土工试验获取并采用现场大比尺试验结果进行校验。通过模拟分级加载,得到了DX桩和直孔桩的抗拔承载力曲线,同时得到了沿桩身的轴力分布,依据这些计算结果展开分析,可以发现DX单桩的抗拔承载力比相同直径的普通直孔桩高出一倍以上,其上下承力盘的发挥作用是由上而下,但当荷载增大到一定程度时,下盘将发挥更大的作用。

This paper analyzes DX single pile with 2 bearing plates on its resistance of uplift load by numerical analysis method. The parameters for analysis are drawn from lab test and verified by large scale loading test of DX piles. The Q-s curve and axial force of DX pile are obtained, and the conclusions based on the analysis are drawn. The uplift bearing capacity of DX single pile is about more than twice larger than that of the normal single pile and its bearing plates work out from the upper to the lower order, while when the bearing capacity reaches certain level, the lower plate will play a more important role.