Relationship between Resilient Modulus and Unconfined Compressive Strength for Lime-Stabilized Soils

This technical note assesses the widely accepted Thompson’s equation used to approximate design resilient modulus ($M_r$) for lime-stabilized soils from the results of unconfined compressive strength ($q_u$) testing. There is limited evidence in the literature to support Thompson’s equation relating $q_u$ and $M_r$ for lime-stabilized soils, and other studies have suggested that the relationship provides an excessively conservative approximation for design $M_r$, specifically above $q_u=\mathrm{1,000}\hspace{0.17em}\text{kPa}$. Laboratory $M_r$ and $q_u$ testing was performed on multiple specimens of three lime-stabilized soils. These data reveal that Thompson’s equation provides a lower-bound estimate of $M_r$ from $q_u$ and that Little’s recommended relationship provides a more reasonable match to the data. This study also illustrated a lack of a clear correlation between $M_r$ and $q_u$.