Sustained amplitude (RSx) and significant duration (Da) spectra for seismic risk assessment in sedimentary basins

Nenad Bijelic, Ting Lin, & Gregory Deierlein

Published September 2020, SCEC Contribution #10022

Recognized predictors of ground motion intensity, such as spectral accelerations (Sa) and significant duration of a ground motion (Da5-75%), overlook potentially important seismogram features that control the structural response. In deep sedimentary basins, for instance, salient features of seismograms include the sustained amplitude of the ground motion as well as period dependent duration effects. We propose two new intensity measures to capture these effects, namely the sustained amplitude response spectrum (RSx) and the significant duration spectrum (Da). RSx is obtained by extending the 1st peak elastic response spectrum to the xth peak, while Da is obtained by extending the concept of significant duration to be period dependent. After defining the metrics, we discuss the properties of RSx and Da spectra for Sa spectrum and significant duration equivalent sets of basin and non-basin ground motions. We also present a case study of collapse risk in a deep sedimentary basin, where RSx and Da spectra allow for improved risk quantification. We conclude with comments on areas where RSx and Da might yield novel results and provide thoughts on potential future research directions.

Key Words
sedimentary basin; collapse risk; intensity measure; sustained amplitude; spectra

Citation
Bijelic, N., Lin, T., & Deierlein, G. (2020, 09). Sustained amplitude (RSx) and significant duration (Da) spectra for seismic risk assessment in sedimentary basins. Oral Presentation at 17th World Conference on Earthquake Engineering (17WCEE).

Related Projects & Working Groups
Characterization of basin effects in simulations for performance assessment of tall buildings, Ground Motion Simulation Validation (GMSV), Earthquake Engineering Implementation Interface (EEII)