UBC Faculty Research and Publications

Estimating Economic Losses of RC Wall Buildings in Sedimentary Basins by Combining Empirical and Simulated Seismic Hazard Characterizations Molina Hutt, Carlos; Kourehpaz, Pouria; Marafi, N.; Berman, J.; Eberhard, M.

Abstract

Studies of recorded ground motions and simulations have shown that deep sedimentary basins can greatly increase the intensity of earthquake ground motions at medium and long periods, i.e. 1-4 s. While future earthquake design provisions are likely to account for basin amplification, the consequences of accounting for these effects are uncertain. By combining empirical and simulated seismic hazard characterizations that account for the effects of basins, this paper estimates key indicators of seismic performance, expressed in terms of earthquake-induced repair costs, for a series of 12-story reinforced concrete shear wall archetype buildings in Seattle, WA. The reference archetype is designed to comply with ASCE 7-16 minimum design requirements, which neglect basin effects. A series of code-prescriptive design enhancements, five in total, are also evaluated. The enhancements include: (a) increasing design forces, (b) decreasing in drift limits, and (c) a combination of these strategies. As an additional reference point, a performance-based design is also assessed. The performance of the archetype buildings is evaluated for the seismic hazard level in Seattle according to the 2018 National Seismic Hazard Model (2018 NSHM), which explicitly considers basin effects. Increasing design forces by 25% combined with a reduction in drift limits to 1.5% was found to be the most efficient of the seven design strategies considered, resulting in a 51% reduction in the average annual losses compared to the reference archetype. Incorporating physics-based ground motion simulations to represent the large-magnitude Cascadia subduction interface earthquake contribution to the hazard results in an average increase in annual losses of 28% compared to the 2018 NSHM.

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Attribution-NonCommercial-NoDerivatives 4.0 International