A Framework to Assess Seismic Resilience of Self-Centering Steel Frame Buildings

Abstract

Resilience can be treated as an integrated measure to assess the seismic performance of buildings. Available methods to assess the seismic performance of self-centering structures mainly consider inter-story drift ratios, peak floor accelerations, and energy dissipative capacities, however, their seismic resilience is poorly understood. This paper proposes a framework to estimate the seismic resilience of self-centering energy dissipative braced steel frame office buildings. In this context, a new damage ratio assessment model is presented to assess functionality. Unlike the traditional method that only considers the economic loss or repair time in the functionality assessment, the proposed model accounts for the contribution of four performance measures such as downtime. To estimate the repair cost, repair time, casualties, and unsafe placarding, the FEMA P58 methodology is used. Based on the proposed model, the new damage ratios and recovery times of the self-centering structure are estimated. Obtained damage ratios are combined with fragility analysis to calculate the functionality loss. After considering an appropriate recovery model, seismic resilience is assessed. For comparison, the traditional method (i.e. HAZUS) is also used to assess seismic resilience. The whole framework is applied to a three-story self-centering energy dissipative braced steel frame, and the results show that the traditional method often underestimates the seismic resilience, and the proposed method may be more suitable for predicting the seismic resilience of self-centering energy dissipative braced steel frame office building. Sensitivity analysis is performed to identify uncertain parameters to which seismic resilience is most sensitive, and the result indicates that the control time and damage ratio at the extensive damage state have a major influence on seismic resilience. The framework can be modified and extended to assess the seismic resilience of ordinary building structures and other complex structural systems such as isolated structures.