Uncertainty and Quality rating in Analytical Vulnerability Assessment

Fragility curves represent a major component of seismic risk and vulnerability assessment of buildings and infrastructure facilities. A recently conducted extensive literature review under the framework of developing the “GEM Guide for Selecting of Existing Analytical Fragility Curves and Compilation of the Database”, shows that there is a wealth of existing analytically derived fragility curves that can be used for future applications. However, the main challenge in using these curves is how to identify and, if necessary, combine suitable fragility curves from a pool of curves with different characteristics and, often unknown, reliability. The present article introduces a rating system that has been developed following detail review and critique of the various methodologies on the derivation of analytical fragility curves that have been generated in the past two decades. The main scope is to provide guidance, either in choosing suitable and robust existing fragility curves or in generating new fragility curves. The quality rating system rates the quality of a curve according to the effect that various parameters, simulation procedures and assumptions on the reliability of fragility curve. It also assists and steers potential analysts towards a better identification and quantification of expected uncertainties throughout the process.