Strength characteristics of the melting silty clay under cyclic loading and the evolution law of hysteresis loop

In seasonal frozen subgrade in the process of melting in spring, especially under the again and again action of cyclic loading, it is easy to cause the mud pumping capacity to significantly reduce to result in disasters phenomena. Current researches of seasonal frozen subgrade mostly stay in the frozen soil and soil after freezing and thawing cycle melt phase, and little is known about the melting soil. In this paper, triaxial monotonic loading and cyclic loading and unloading tests are carried out on the melting silty clay under different melting temperatures, negative freezing temperatures, water content and confining pressures. It is found that the strength of the samples under cyclic loading and unloading is lower than that of most samples under monotone loading, and each cycle will cause certain damage to the samples. Because there is a large amount of water and confining pressure during melting, the peak strength of the sample decreases with the increasing water content and the decreasing confining pressure. The negative temperature of freezing and melting temperature affect the melting rate. The lower the temperature, the higher the strength in the early stage and the weaker the influence with time. The damage variables are defined by the rebound modulus of the hysteresis ring. Under the influence of different factors, the difference in the growth of damage variables lies in the difference in the corresponding cycle times when damage develops rapidly and slowly. Dissipative energy is defined based on the area of hysteresis ring, but there is a negative correlation between the damage variable and dissipative energy.