Characterization of Long Period Strong Ground Motion

The performance-based earthquake engineering requires reliable assessment of long-period ground motion particularly for tall buildings, base-isolated structures, long bridges, and structures that are designed to deform beyond the elastic range. The important issues involved in such assessments are: Empirical and theoretical tools for prediction of displacement response spectra; Analysis and incorporation of near fault effects; Spectrum scaling for different damping ratios and; Time domain simulation of long-period ground motion. These issues are elaborated through (۱) the principles for modification of design basis spectra in the long-period range; (۲) guidelines for time domain simulation of long-period ground motions; and (۳) rules for selecting and scaling ground motion records to address long-period effects. This paper aims to review and discuss these issues with developments on GMPRs for peak ground displacement and ۱۰s spectral acceleration, and example applications on earthquake hazard assessment for ۱۰s spectral accelerations and its deaggregation in the Marmara Region, Turkey.