Deformation characteristics and shakedown behaviors of frozen silty clay under complex cyclic stress paths

The deformation characteristics and stability behaviors of frozen soil under complex cyclic stress paths play an important role in the long-term stability of cold region engineering. To analyze the influences of different complex cyclic stress paths on the deformation characteristics and shakedown behaviors of frozen soil, five cyclic stress paths are designed at the same level, namely triaxial cyclic stress path (TCSP), directional cyclic stress path (DCSP), circular cyclic stress path (CCSP), elliptical cyclic stress path (ECSP) and heart-shaped cyclic stress path (HCSP). The axial cumulative plastic strains of the samples are analyzed, and the results are evaluated by three shakedown evaluation criteria. The axial cumulative plastic strains under five cyclic stress paths at different temperatures satisfy the following: DCSP > ECSP > HCSP > CCSP > TCSP. The directional cyclic stress path has the greatest influences on the shakedown behaviors of the soil, and the failure belongs to the incremental one under the three criteria. At the temperature of -15℃, the results of the HCSP and ECSP tests also belong to the incremental failure under the evaluation of Chen criterion.