Accounting for ground-motion uncertainty in empirical seismic fragility modeling
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Author / Producer
Date
2024-11
Publication Type
Journal Article
ETH Bibliography
yes
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Abstract
Seismic fragility models provide a probabilistic relation between ground-motion intensity and damage, making them a crucial component of many regional risk assessments. Estimating such models from damage data gathered after past earthquakes is challenging because of uncertainty in the ground-motion intensity the structures were subjected to. Here, we develop a Bayesian estimation procedure that performs joint inference over ground-motion intensity and fragility model parameters. When applied to simulated damage data, the proposed method can recover the data-generating fragility functions, while the traditionally used method, employing fixed, best-estimate, intensity values, fails to do so. Analyses using synthetic data with known properties show that the traditional method results in flatter fragility functions that overestimate damage probabilities for low-intensity values and underestimate probabilities for large values. Similar trends are observed when comparing both methods on real damage data. The results suggest that neglecting ground-motion uncertainty manifests in apparent dispersion in the estimated fragility functions. This undesirable feature can be mitigated through the proposed Bayesian procedure.
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Publication status
published
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Editor
Book title
Journal / series
Volume
40 (4)
Pages / Article No.
2456 - 2474
Publisher
SAGE
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
Bayesian inference; ground-motion uncertainty; empirical fragility functions; Markov Chain Monte Carlo; fragility analysis
Organisational unit
02605 - Institut für Baustatik u. Konstruktion / Institute of Structural Engineering