长期循环荷载作用下管桩侧阻力试验研究

对软土地区静压管桩的静、动载试验结果进行分析,发现在工作荷载作用下软粘土中桩侧摩阻力呈抛物线分布,在循环动荷载下存在退化效应,并对此进行初步分析。分析结果表明:在动力循环荷载作用下,桩身上部软土层出现弱化现象,导致桩身上部的侧摩阻力减小,桩的下部粉质粘土与粉砂层侧摩阻力有所增加,但这种现象随动载循环次数的增加趋于稳定。

Experimental Study of Side Frictional Resistance of Pipe Piles Under Long-Term Cyclic Load

The results of static and dynamic load experiment for statically-loaded pipe piles in the soft soil area are analyzed.It is found in the experiment that the side frictional resistance of the piles in the soft clay under working load behaves in a state of parabola distribution and has retrograde effect under cyclic dynamic load.Such phenomenon as mentioned is preliminarily analyzed and the results of analysis indicate that under the cyclic dynamic load,the soft soil around the upper parts of the piles become weakened,resulting in a decrease of the side friction resistance of the upper parts of the piles and a little increase of the frictional resistance of the lower parts of the piles in the silty clay and silty sand.However,the phenomenon will tend to be stable with the increase of the cycling times of the dynamic load.