Amplification characteristics at artificial Island considering viscoelastic effects of cohesive soil

The aim of the present paper was to perform a one-dimensional finite element analysis of layered ground according to a cyclic viscoelastic-viscoplastic theory. In order to estimate the viscous effects of clay over a wide range of strain levels, a viscoelastic-viscoplastic constitutive model for clay was proposed. First, we confirmed the performance of the proposed model by simulating cyclic undrained triaxial tests to determine the cyclic strength and deformation characteristics of natural marine clay. The proposed model was then incorporated into an effective stress-based amplification characteristics analysis to estimate the effects of an intermediate clay layer on the behavior of sand layers. The results show that a cyclic viscoelastic-viscoplastic constitutive model can provide a good description of dynamic behavior including viscoelastic effects, within a small strain range.   Key words: Constitutive model, amplification characteristics, viscoelastic, viscoplastic, clay.