The simulations carried out to date for nonlinear seismic response have essentially been one- or two-dimensional. Nonlinear earthquake simulation for three-dimensional realistic large basins with adequate soil plasticity models remains one of the most difficult challenges in geotechnical earthquake engineering. However, recent advances in high performance computing technology and further understandings in soil plasticity modelling have made the large-scale nonlinear earthquake simulations feasible on parallel computers.
The complexity of soil behavior in an actual problem and the variation of test data from conventional tests make the selection of a suitable soil model difficult. The various soil models have strengths and weaknesses. The search for a good constitutive soil model is not yet over, and there always is room for special soil models for particular kinds of problems. Nevertheless, one should take into consideration both physical reasonableness and mathematical tractability into the selection of an appropriate soil model for use in large-scale three-dimensional dynamic simulations.
For developing a finite element computer program for large-scale nonlinear seismic response analysis on a parallel computer, the solution aspects that need to be addressed are the accurate integration of the nonlinear constitutive model, stability of explicit solution of the equations of motion, and appropriate data parallel implementation. The first two aspects influence the convergence of the solution process, while the last influence the computational efficiency of large-scale problems on parallel computers.