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

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.