University of New Hampshire
Mentor: Dr. Ricardo Medina, UNH Department of Civil Engineering
Influence of Aftershocks on Non-Linear Seismic Response of Deteriorating SDOF Systems
In the event of an aftershock or a sequence of aftershocks, the already main shock-damaged building may collapse due to additional impacts. To miti¬gate the risks and damages to buildings due to aftershocks, a comprehensive understanding of the dynamic response and collapse potential of buildings exposed to aftershocks is necessary. This study concentrates on the identification of the main ground motion and structural parameters that influence the dynamic response and collapse potential of deteriorating structures exposed to main shock-aftershock sequences. The structural systems of interest are buildings that can be modeled as Single-Degree-Of-Freedom (SDOF) systems. Collapse fragilities curves are developed to quantify the collapse potential of SDOF systems as a function of relevant ground and structural parameters. Ground motions corresponding to rock, soil, and stiff-soil sites are used. Nonlinear time history analyses are conducted with SDOF systems with various strengths, periods of vibration, damping ratios, hysteretic behavior, and cyclic deterioration characteristics. The results from this study are intended to provide information needed to determine whether aftershock hazards should be explicitly accounted for in the seismic design and evaluation of buildings.