PROBABILISTIC SEISMIC DEMAND MODELS AND RISK ASSESSMENT FOR HIGH-RISE BUILDINGS

It presents a Bayesian-based seismic risk assessment methodology for high-rise buildings, in which, uncertainties associated with the seismic hazard model, input seismic loads, structural properties, and the demand model are taken into consideration. Using the earthquake data from 1970-2017 in Dali, the presented method is discussed in detail. Based on the traditional probabilistic seismic hazard analysis (PSHA), a Bayesian-based PSHA (B-PSHA) method is proposed herein. The Bayesian updating rule is used to develop the posterior probability distributions of the unknown parameters in the hazard model. The probabilistic demand model is constructed by the Bayes theory, which will be applied to account for the epistemic uncertainty associated with the demand model for seismic fragility analysis. The Bayesian-based risk assessment is implemented on a 42-story steel frame-reinforced concrete (RC) core tube building. The results indicate that: A more rational seismic hazard model can be obtained by the B-PSHA method; Erroneous estimates of fragility may be made when ignoring the uncertainty in the unknown parameters of the demand model; Seismic loading directions will have significant impacts on the seismic risk. The presented risk assessment method provides an effective approach to investigate the effects of both aleatory and epistemic uncertainties and is beneficial for the progress of seismic resilience assessment and structural design theory.