Evaluation of Subgrade Resilient Modulus using CBR Test Data to Facilitate Mechanistic-Empirical Pavement Design (MEPD)

Sri Lankan road pavement design has relied on empirical design guidelines, and it is now transforming to a more modern approach known as the Mechanistic-Empirical Pavement Design (MEPD) method, aligning with global best practices. One crucial input parameter in this new methodology is the Resilient Modulus (RM) of unbound materials. Determination of RM and establishment of typical values is essential to implement the MEPD. This study has devoted significant attention to the RM evaluation process and developing predictive models for determiningRM from CBR values. Furthermore, typical RMvalues for locally available soil types have been established. In addition to that, ageospatial database has been established with information on soil properties and RMvalues throughout Sri Lanka. This database is a valuable resource for M-E road pavement design, providing quick reference data to conceptual designs and Level 3-MEPD.