The impact of a PEER funded research project "Reduced-Order Models for Dynamic Soil-Structure Interaction Analyses of Buried Structures" is highlighted below. The project Principal Investigator (PI) is Domniki Asimaki, Professor of Mechanical and Civil Engineering, Caltech. The Co-Principal Investigator is Elnaz Esmaeilzadeh Seylabi, Assistant Professor, University of Nevada, Reno. The research team includes Kien T. Nguyen, Postdoctoral Researcher, Caltech.
The frequency-dependency of SIF for the design of shallow and deep foundations has been established and widely accepted by the profession. However, there are no equivalent methods to account for the frequency-dependence of SIF in the case of horizontally oriented buried structures. Our recently published and ongoing work has shown that the response of these structures to dynamic loading is both strongly nonlinear (as opposed to the bilinear state-of-the-art assumptions) and strongly frequency dependent. The proposed research will benefit this problem two-fold: (i) the community database of dynamic SbSI functions (springs and dashpots) will be generated in a tabulated or graphical form, to enable their use by practitioners who are interested in selecting the most appropriate values of springs and dashpots for this class of problems; and (ii) the proposed OpenSEES uniaxial material model that will account for the frequency-dependence of nonlinear SIF will provide a robust and versatile tool to improve the analysis of buried structures under seismic excitation, while maintaining computational efficiency. This in turn will benefit performance-based earthquake engineering methods by providing a physics-based model to account for the effects of spatial variability and incoherency in the seismic demand of extended structures.