Abstract: To capture the influence of loading rate on the deformation process of structured soft clay, applying the approach used in the unified hardening model (UH model) to describe time effects, an equivalent time term is introduced into the yield function ( ^-t) of the structured UH model, and then a structured UH model for soft clay considering loading rate is extended. In the equivalent time term, the internal variable R of the original structured UH model is transformed into R_t to account for time-driven strain. The presented structured UH model considering time effects comprises a total of 8 parameters, all of which can be determined through routine soil tests. Comparisons between model predictions and experimental data demonstrate that the presented model is qualified to reflect the influence of loading rate on structured soft clays reasonably.

Key words: structured soil, time, unified hardening, loading rate