超长大直径钻孔灌注桩的承载力检测与分析

Test and Analysis of Bearing Capacity of Overlong Major Diameter Bored Pile

介绍了用锚桩反力法对某近海桥梁工程试验桩进行承载力检测的情况,给出了该桩的极限承载力推荐值及桩侧摩阻力实测值;分析指出大直径钻孔灌注桩的尺寸效应、成孔时间及泥浆厚度是桩侧摩阻力实测值小于勘察报告推荐值的主要原因;并提出对桩径小于800mm的钻孔灌注桩,无论是砂层还是粘性土层,同样存在桩侧摩阻力尺寸效应现象。

In this paper, checking the bearing capacity of testing pile in a bridge engineering offshore by method of anchor pile reaction force is introduced, the suggested limit bearing resistance value of pile and measured friction resistance value of side pile are calculated ; size effect of major diameter bored pile, time for the pore forming and the thickness of the mud being the main reason that side friction resistance measured value is lower than the suggested value is analyzed; for bored pile diameter less than 800mm, the side pile resistance size effect exisits no matter sand layer or clayey layer.