Utilization of physics-based ground motion simulations for tall building risk assessment

Nenad Bijelic, Ting Lin, & Gregory Deierlein

Published June 2018, SCEC Contribution #7997

This paper presents an overview of the recent research into utilization of simulated ground motions for engineering performance assessment of tall buildings. The first part of the paper deals with validation of simulated ground motions to demonstrate that simulated motions can reliably capture features that have a significant effect on structural response. In particular, hybrid-broadband ground motions simulated using the Southern California Earthquake Center’s (SCEC) Broadband Platform (BBP) are validated through comparative assessments of building performance obtained using sets of recorded and simulated ground motions. An archetype 20-story tall building is analyzed under comparable sets of simulated and recorded motions at increasing levels of intensity to check for statistically significant differences between responses. These comparisons yield similar results in most cases but also reveal instances where certain simulated ground motions can result in biased responses. Moving beyond validation, the paper also explores collapse performance of the archetype tall building at sites in the Los Angeles basin utilizing the ground motions simulated as part of the SCEC CyberShake project. The collapse risks are obtained using large datasets (~500,000 ground motions per site) of unscaled, site-specific simulated seismograms. Collapse risk from direct analysis of simulated motions is contrasted with risk estimates obtained using “conventional” approaches relying on recorded motions coupled with probabilistic seismic hazard assessments from the U.S. Geological Survey. Instances where the two approaches yield significantly different estimates are highlighted. Further, deaggregation of collapse risk is used to identify the relative contributions of causal earthquakes. Opportunities for continued research are discussed.

Key Words
tall buildings, simulated ground motions, validation, performance-based engineering

Citation
Bijelic, N., Lin, T., & Deierlein, G. (2018, 6). Utilization of physics-based ground motion simulations for tall building risk assessment. Oral Presentation at 16th European Conference on Earthquake Engineering.

Related Projects & Working Groups
Ground Motion Simulation Validation (GMSV) Technical Activity Group (TAG), Earthquake Engineering Implementation Interface (EEII)