Development of a simplified deformation-based method for seismic vulnerability assessment

The state-of-the-art earthquake loss estimation techniques make use of pushover analysis to define the performance of structures under earthquake loading, represented by a demand spectrum whose ordinates reflect the inelastic response. The performance point defined in this way is then used as input to the fragility or loss curves. This rigorous approach represents the earthquake actions by a parameter that is known to have a good correlation with damage and also takes into account the dynamic characteristics of different buildings. However, for many applications, the available data on key input parameters, such as soil conditions and the type and distribution of the exposed building stock, are limited to the extent that the rigorous capacity spectrum approach can become either impractical or unjustified. It is for such case scenarios that a much simpler deformation-based assessment methodology, presented herein, has been developed. The proposed method possesses all the inherent advantages of a displacement-based approach, whilst reducing the required calculations by one or more orders of magnitude when compared to conventional vulnerability assessment procedures.