Triaxial testing and model study on lime modified dispersive soil considering age effects

This study investigates the influence of age on the mechanical properties of lime-modified dispersed soils through consolidation undrained triaxial tests conducted at various age (t) and lime content (a). Empirical equations for Duncan-Chang model parameters K, n, c, and φ incorporating the age factor were established based on experimental results, focusing on lime modification at 2% content. The stress-strain curves of dispersed soils exhibit strain-hardening characteristics, with stress levels increasing notably with age, displaying significant variation between short and long durations. Conversely, the stress-strain curve for lime-modified dispersed soil at 2% content shows strain-softening behavior. Age exerts a substantial influence on model parameters K, n, c, and φ of the Duncan-Chang model, with a minor impact on Rf. The modified model demonstrates a strong fit to stress-strain curves of lime-modified dispersed soil before reaching failure, validated against experimental data at age of 14 days and 90 days. Importantly, the modified model accurately predicts stress-strain relationships for modified soils over extended age beyond 28 days, providing meaningful insights for the long-term stability assessment of soil-modified structures.