加载卸载对人工冻结土强度与变形的影响

Influence of loading and unloading on strength and deformation of frozen soil

加载卸载两种应力路径下冻土应力 -应变曲线均呈双曲线型 ,但其变形过程明显不同。减载应力路径下的屈服强度明显小于增载应力路径下的 ,且随着围压的增大 ,其差异愈来愈大 ,但其破坏变形却基本无大的差异。冻土的屈服强度和破坏变形均随温度的降低而增加 ,但加载下的强度值和破坏变形明显大于减载下的 ,并随着温度的降低 ,这种差值愈来愈大。

Based on a series of tests that simulated the consolidating and freezing processes of foundation and then shearing under loading and unloading, it is found that the yielding strength under unloading is obviously less than that under loading and the difference of the yielding strength between these two stress paths increases with the confining pressure, but the failure strains under the two stress paths do not differ greatly. With the decrease of temperature, the yielding strength and failure strain increase, but the yielding strength and failure strain under unloading are obviously less than that under loading and their differences also increase with a decreasing temperature.