Using a displacement-based approach for earthquake loss estimation

A displacement-based earthquake loss assessment procedure currently under development is presented. Predictions of the degree of damage to buildings under both ground shaking and liquefaction-induced ground failure can be carried out with this method. Earthquake actions and structural reactions are represented by displacements following the observed correlation between building damage and lateral displacements. The main concept is to compare the mechanics-derived displacement capacity of the building stock and the imposed displacement demand from the earthquake. A probabilistic framework has been incorporated to account for the epistemic (knowledge-based) uncertainty in the capacity parameters. Options for treating the aleatory variability in the ground motion are presented for estimates of losses from single and multiple earthquake scenarios. A discussion of the influence of the epistemic uncertainty on the results of a loss model is also presented. The method can be calibrated-for different locations and building practices and this advantage forms the base for a proposed new approach for calibrating seismic design codes.