Seismic vulnerability assessment through explicit consideration of uncertainties in structural capacities and structural demands

Abstract

Earthquakes are among the most important natural hazards confronting engineers, regulatory authorities, and the public at large. The assessment of structural seismic vulnerability has become the subject of intensive research. In this paper, a mathematical framework for seismic vulnerability assessment of building structures is presented, and the concept of vulnerability function is introduced and mathematically described, which is integrally related to the fragility assessment and reflects the susceptibility of a system to serious consequences. The limit state of a building structure is stated as the structural demand exceeding the structural capacity, so the methodology is developed based on a systematic treatment of uncertainties in seismic hazard, structural demands due to seismic hazard, and capacities of building structures in resisting limit states. The methods and assessment procedures are illustrated through a steel building frame, showing the presented methodology is an efficient tool in support of seismic vulnerability assessment. The explicit consideration of uncertainty is an integral part of the engineering risk management and decision process, and the methodology can also be applied to other buildings, bridges or civil infrastructure systems.