Impacts of Fault Rupture Characteristics and Shallow Basin Amplification on the Response of Ductile Buildings to Near-Fault Physics-Based Simulated Ground Motions
Session: Physics-Based Earthquake Rupture Modeling and Strong Motion Simulations II
Type: Oral
Date: 4/23/2021
Presentation Time: 03:00 PM Pacific
Description:
Broadband physics-based earthquake simulations were utilized to study the impacts of fault rupture and site characteristics on the seismic risk to code-compliant modern reinforced concrete buildings with different dynamic properties. High-performance computers at Lawrence Berkeley National Laboratory were employed to conduct nonlinear structural response history simulations over large computational domains covering a 100-km × 40-km, and containing a highly dense grid of buildings spaced at 1 km. The synthetic earthquake ground motions were generated using kinematic fault rupture models with varying rupture characteristics to represent canonical shallow crustal earthquakes, and resolved up to frequencies of 5 Hz. The spatial variability of the ground motion intensity and structural demands was examined, with particular focus on two aspects: (1) the impact of incorporating regions of high slip (asperities) along the fault (also known as the hybrid rupture approach), and (2) the amplification due to the presence of the shallow sedimentary basin, and the proximity of the fault and the buildings to the basin edge. The study reveals substantial variability in the ground motion intensity and structural risk within about 15 km of the fault, particularly when the rupture incorporates concentrated high-slip patches. The effects of the slip asperities and the basin edge on the ground motion components normal and parallel to the rupturing fault appear to differ somewhat significantly in the near-fault region, prompting questions regarding appropriate selection of fault-normal and fault-parallel ground motion components for near-fault engineering risk analysis. Compared to available real recorded motions, the results of the study suggest that the simulated motions using the hybrid rupture approach may offer reasonable structural risk estimates for low-frequency structures and conservative estimates for high-frequency structures.
Presenting Author: Maha Kenawy
Student Presenter: No
Authors
Maha Kenawy Presenting Author Corresponding Author mkenawy@unr.edu University of Nevada Reno |
David McCallen dmccallen@unr.edu University of Nevada Reno |
Arben Pitarka pitarka1@llnl.gov Lawrence Livermore National Laboratory |
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Impacts of Fault Rupture Characteristics and Shallow Basin Amplification on the Response of Ductile Buildings to Near-Fault Physics-Based Simulated Ground Motions
Category
Physics-based Earthquake Rupture Modeling and Strong Motion Simulations