DYNAMIC PROPERTIES OF COHESIVE SOILS TREATED WITH LIME

Dynamic properties of three compacted cohesive soils, kaolinite, sodiu m montmorillonite, and calcium montmorillonite, which were treated wit h up to 8% lime, were determined under a wide range of strains and con fining pressures. The soils had plasticity indices ranging from 18 to 514. Lime treatment affected and improved the dynamic properties of th e three soils. For all of the soils, the cyclic secant shear modulus d ecreased and the equivalent viscous damping ratio increased with incre ased strain levels. By increasing the lime content, the shear modulus of the sodium montmorillonite dramatically increased and the damping r atio decreased. Similar behavior was noted for the calcium montmorillo nite. The difference in response between the two montmorillonite soils was attributed to the presence of calcium already in the calcium mont morillonite soil. The response of the kaolinite soil to lime treatment was moderate. Normalized plots of treated soils with respect to value s of untreated soils are presented. These plots provide a useful guide for the preliminary estimation of lime requirements to improve the dy namic properties of soils.