Advanced dynamic nonlinear schemes for geotechnical earthquake engineering applications: a review of critical aspects

Nonlinear time domain numerical approaches together with elasto-plastic effective stress soil constitutive models are nowadays available to geotechnical researchers and practitioners interested in geotechnical earthquake engineering. The use of such advanced two- and three-dimensional schemes allows the analysis and design of complex geotechnical structures within a performance-based framework, considering the build-up of excess pore water pressure during the earthquake, dynamic interaction between the soil deposit and the above surface buildings and infrastructures and effects of multi-directional seismic loading. Within this context, the paper focuses on the dynamic finite element (FE) method and presents a review of the key ingredients governing its predictive capabilities. These include i) the description of the fully coupled solid-fluid interaction formulation and time integration, ii) the calibration of Rayleigh damping and the soil constitutive model parameters, iii) prescription of the boundary conditions for the generated mesh and iv) input motion selection/scaling strategies. For each of the above points, the paper summarises the current knowledge and best practice, with the aim of providing protocols for a confident application of nonlinear FE schemes to evaluate the performance of critical geotechnical infrastructures. Useful hints to promote familiarity of advanced nonlinear soil dynamic analysis among geotechnical practitioners and to indicate areas for further improvement are also highlighted.