Assessment of damping predicted by kinematic hardening soil models during strong motions

The damping characteristics of soils are not accurately predicted in most constitutive models. This paper examines the cyclic performance of kinematic hardening models from the a posteriori analysis of free-field ground response results. Shear stress−strain histories, recorded at the local level, are used to estimate the real variation of soil shear modulus and material damping characteristics induced by earthquakes of different seismic intensity. The results from dynamic finite-element simulations of a specific site indicate that the frequency of occurrence of the largest closed cycles, induced by strong motions, is typically very low. This appears to contradict the usual assumption that kinematic hardening models tend to over-predict the hysteretic damping at large shear strains, thus demonstrating their effectiveness in capturing wave propagation during intense seismic loading.