Evaluation of Modulus of Elasticity and Modulus of Subgrade Reaction of Soils Using CBR Test

This paper presents the procedure of evaluation of the modulus of elasticity (E) and the modulus of subgrade reaction (ks) value based on the California Bearing Ratio (CBR) tests and FEM analysis. The pressure-displacement response of the soil in the CBR mould is simulated using Cosmosworks FEM model where the soil, the load plunger, and the steel mould of CBR are represented. The correlation of Modulus of Elasticity (E) with California Bearing Ratio (CBR) is developed based on the elastic properties of the soil sample. Furthermore, the correlation between E and CBR is proposed. Using the E values, modulus of subgrade reaction can be calculated and vice versa as well. Thus CBR test is expected to simplify the effort in determination of the modulus of subgrade reaction which is used in Foundation design, soil structure interaction, design of highway formations etc.