Cyclic mechanical loading of unsaturated silty clay soils

Cyclic mechanical loading of soils due to natural causes such as earthquakes or due to loads coming from structures causes the accumulation of strains and excess pore-water pressures endangering the long term serviceability and stability of the structures built on them. In this study, un-drained cyclic loading tests at 0.1 Hz frequency are carried out on a normally consolidated unsaturated silty clay soil at different deviatoric stresses for up to around 1400 cycles. The results of the tests, which were performed using a recently developed cyclic electromechanical tri-axial device, show a significant dependence of the cyclic mechanical behavior of the silty clay soil, such as in the form of cyclic axial and accumulated plastic strains, on the number of cycles and applied deviatoric stresses.