中文摘要：

选取典型的中砂作为土体，通过单桩的室内模型试验方法研究了单桩在砂土中的桩身滞回圈随着循环次数和加载力大小改变的变化规律，试验结果表明，水平方向循环荷载作用下，在高次循环加载中，滞回圈的变化主要为力逐渐变大、位移逐渐变小，变化主要集中在前1万次左右，之后趋于稳定；随着加载力的逐渐变大，滞回圈的变化速度也逐渐加快，很快就趋于稳定。

英文摘要：

Selecting typical medium sand as the soil,through the indoor model test of single pile method to study the pile body hysteresis loops of single pile in the sand as the cycles and the changing rule of the loading force change. The test results show that the horizontal cyclic loads,in high cyclic loading,the change of the hysteresis loop is mainly do to grow bigger and smaller displacement gradually,before changes are mainly concentrated in ten thousand times or so,after stable,as the loading force increases gradually,the change of the hysteresis loop speed also gradu-ally accelerated,stabilise soon.