Abstract:
The dynamic properties of Guilin red clay exhibit significant regional variability. This study investigated the softening behavior of saturated remolded Guilin red clay under cyclic loading through a series of undrained dynamic triaxial tests. The influences of confining pressure, cyclic stress, consolidation ratio, and compaction degree on the evolution of the softening index were systematically examined. Results indicate that the softening index develops more rapidly with increasing cyclic stress, while greater compaction effectively suppresses softening. Higher effective confining pressure also retards the softening process. A critical consolidation ratio was identified: below this threshold, dynamic strength improves with increasing consolidation ratio, whereas above it, strength declines. Based on the observed variations in axial strain, softening index, and excess pore water pressure, the strain inflection point is validated as a more rational failure criterion than conventional fixed strain limits. Furthermore, a non-monotonic asymmetric empirical softening model was developed and validated for its applicability and accuracy. These findings provide a theoretical basis for dynamic stability design and assessment in Guilin red clay regions.