Seismic Response Assessment of Discrete and Continuous Structural Systems via Shaking Table Testing
- Rodriguez Burneo, Andres
- Advisor(s): Restrepo, Jose I
Abstract
Over the years, shaking table tests have provided invaluable data for understanding the dynamic response of structural systems. Shaking table models are often scaled down to accommodate the size of elements commonly studied in civil/structural engineering. However, geometrical scaling brings similitude challenges. The availability of large shaking tables has enabled the evaluation of full-scale structures and helped overcome the difficulties of scaling and similitude. This dissertation presents two independent research projects on structural systems using different large-scale shaking tables tests.
The first project consisted of the seismic response assessment of a multi-block tower structure built using discrete concrete blocks. The project was a proof of concept for an energy storage facility. Three 1:25 scale tests were part of a larger research campaign involving smaller physical and computational models. Results from this study contributed to the validation of the computational models and the theoretical background required to compare results at different scales. Moreover, it was possible to evaluate the behavior of this type of discrete structures, including energy dissipation and collapse mechanisms.
The second project involved an experimental and computational study of the reaction mass-soil dynamic response and interaction of the recently upgraded UC San Diego Large Outdoor Shake Table. The experimental campaign encompassed full-scale forced vibration tests of the reaction mass to characterize the response of the structure-soil system. The tests aimed to evaluate if the system's dynamic characteristics had significantly changed post-upgrade and allowed to determine their low-strain natural frequencies and effective system damping. Furthermore, the extensive experimental data motivated the creation of a detailed three-dimensional continuum model of the reaction mass-soil system, calibrated with experimental data in a parametric study. The accurately calibrated model will allow us to estimate the response of the reaction mass under any excitation induced by the shake table and ensure its adequate operation. Finally, availability of large-scale experimental data allowed to study modeling techniques commonly used in continuum soil-structure-interaction and provide suggestions to simplify these types of models and promote their use in professional practice.