砂土中齿桩竖向承载性状试验研究

设计多组缩尺模型试验,设定齿部结构的齿长、齿部结构数量为变量参数,通过具有齿部结构的模型桩与光面模型桩的加载试验对比分析,探究砂土中齿桩在竖向荷载下的承载特性及侧阻变化的情况。试验结果表明:齿数相同的情况下,桩侧阻力与齿长的关系呈现线性正相关;齿长相同的情况下,桩侧阻力与齿数的关系呈现线性正相关;齿数对侧阻的影响较大,而齿长对竖向承载力的影响较大;在增加齿数后,由于桩侧粗糙度的增加以及齿部给桩侧摩阻软化带来的改性,桩侧摩阻所能分担的上部荷载愈发增大;齿桩的齿部结构通过增强桩土界面强度,进而改变桩土之间剪切面的发生位置及其剪切带的厚度,从而提高桩的竖向承载力。该研究可丰富小改截面桩的研究领域,为桩基的创新研究提供参考依据。

Experimental study on characteristics of tooth pile under vertical load

To explore the bearing characteristics and lateral resistance changes of the tooth pile under vertical load in the sand foundation, we designed several sets of model tests, in which the tooth length and the teeth number of the pile were selected as parameters, and the results of tooth pile were compared with that of smooth surface pile. The test results showed that the pile side resistance was positive linear correlated with tooth length when the teeth number was the same. Similarly, when the tooth length was the same, the pile side resistance was positive linear correlated with the teeth number. The teeth number had a great influence on the side resistance. However, the tooth length had great influence on the vertical bearing capacity. When teeth number increased, the upper load could be shared by the pile side friction, due to the roughness increase of the pile side and the modification of tooth effect to friction softening. The tooth structure of the tooth pile enhanced the vertical bearing capacity by enhancing the strength of the pile-soil interface, and changing the occurrence position and thickness of the shear zone in the interface. This research can enrich the study on small modified section piles and provide reference for the innovative of pile foundation.