Dynamic properties of cohesive soils treated with lime

Dynamic properties of three compacted cohesive soils, kaolinite, sodium montmorillonite, and calcium montmorillonite, which were treated with up to 8% lime, were determined under a wide range of strains and confining pressures. The soils had plasticity indices ranging from 18 to 514. Lime treatment affected and improved the dynamic properties of the three soils. For all of the soils, the cyclic secant shear modulus decreased and the equivalent viscous damping ratio increased with increased strain levels. By increasing the lime content, the shear modulus of the sodium montmorillonite dramatically increased and the damping ratio decreased. Similar behavior was noted for the calcium montmorillonite. The difference in response between the two montmorillonite soils was attributed to the presence of calcium already in the calcium montmorillonite soil. The response of the kaolinite soil to lime treatment was moderate. Normalized plots of treated soils with respect to values of untreated soils are presented. These plots provide a useful guide for the preliminary estimation of lime requirements to improve the dynamic properties of soils.