Ricardo Taborda

We present a study of the synthetic earthquake ground motion obtained in a three-dimensional model of a realistic basin, taking into consideration the nonlinear characteristics of the soil in the basin. In this initial analysis, nonlinearity is implemented by modeling the soil with the von Mises and Drucker-Prager formulation for elastoplastic materials. We simulate a hypothetical scenario earthquake, and solve the inelastic wave equations by means of the finite element spatial discretization method using an in-house developed octree-based parallel software for the simulation of ground motion due to earthquakes generated by kinematic faulting. The solution of the resulting semi-discrete nonlinear elastoplastic ordinary differential equations is computed explicitly step-by-step. The simulation is conducted on a parallel computer where each processor receives a portion of the unstructured mesh and computes the solution in an element-by-element fashion. We compare the results of the elastic and inelastic response of the basin. The comparison reveals the importance of considering nonlinear soil conditions and gives relevant insights about the influence of three-dimensionality for a problem that is often simplified into one- or two-dimensional models. Our work ultimately aims at fully incorporating nonlinearity into large-scale earthquake simulations, which to date do not yet consider this important aspect in three-dimensional strong ground motion modeling and analysis.