Calibration of the mechanical parameters for the numerical simulations of dynamic centrifuge experiments

Numerical analyses could represent a very useful tool to model the seismic behavior of infrastructures. Sometimes this is a preferableway to study problems of seismic soil/structure interaction, because true scale monitoring and physical modeling could be not convenient. For the purpose of dynamic analyses, recent release of PLAXIS 2D implements the Hardening Soil Small Strain model (HSSS), which is a modification of the isotropic hardening model (HS), including the shear strain dependence of soil stiffness modulus and damping ratio. Moreover, the non-linear stress-strain relation of HS model is used to represent both transient and permanent behavior of the soil under cyclic dynamic actions. In this paper, the HSSS material model was used to reproduce the behavior of shallow tunnels under dynamic loadings. The input mechanical parameters for a Leighton Buzzard sand (fraction E) were calibrated on the basis of advanced laboratory tests and experimental evidence of dynamic centrifuge models. The results were finally compared to the physical modeling findings.