Impacts of Seattle Basin on Performance of RC Core-wall Buildings During M9 Cascadia Subduction Zone Earthquakes
United States Geological Survey and University of Washington researchers generated thirty, physics-based, ground-motion simulations that provided the opportunity to evaluate the potential impacts of sedimentary basins on building performance during an M9 earthquake on the Cascadia Subduction Zone. For periods ranging from 1.5s to 4s, the spectral accelerations in Seattle for many simulated motions exceeded the risk-targeted maximum considered earthquake (MCER) ground motions that do not account for basin effects. The period-dependent variation in the spectral amplification also led to ground motions with spectral shapes that further increased the damage potential of the ground motions.
The impacts of these motions were evaluated for thirty-two archetypes, ranging from 4 to 40 stories, representing modern residential concrete wall buildings in Seattle. The archetypes were developed to reflect the minimum requirements of the ASCE 7-16 code provisions. Maximum story drifts and collapse probabilities were computed using nonlinear dynamic analysis and a slab-column fragility function that was derived from experimental data. For motions that did not account for the Seattle Basin, the average collapse probability for the archetypes was less than 10% for an M9 earthquake. The average collapse probabilities for these buildings increased to 21% when the effects of the Seattle Basin were considered. The 50-year collapse risk was estimated by accounting for crustal, intraslab and interface events, as well as material, design and modeling uncertainties. For buildings with 4 to 24 stories, the Seattle Basin increased the average 50-year collapse risk for the reference archetypes from 0.7% to 1.8%, which significantly exceeds the target value of 1%.
Session: The Effects of Sedimentary Basins on Earthquake Ground Motions I
Type: Oral
Room: Cedar
Date: 4/20/2022
Presentation Time: 02:00 PM Pacific
Presenting Author: Marc O. Eberhard
Student Presenter: No
Additional Authors
Marc Eberhard Presenting Author Corresponding Author eberhard@uw.edu University of Washington |
Nasser Marafi nasser.marafi@rms.com RMS |
Jeffrey Berman jwberman@uw.edu University of Washington |
Erin Wirth emoriarty@usgs.gov U.S. Geological Survey |
Arthur Frankel afrankel@usgs.gov U.S. Geological Survey |
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Impacts of Seattle Basin on Performance of RC Core-wall Buildings During M9 Cascadia Subduction Zone Earthquakes
Category
The Effects of Sedimentary Basins on Earthquake Ground Motions
Description