Probabilistic assessment of structural damage from coupled multi-hazards

Evaluating and predicting structural damage from multi-hazards is a complex task mainly due to the varying ways in which hazards affect structures. Also, different damage scales that employ different parameters and criteria are used for evaluating the hazards, making a connection between the damage assessment of two or more hazards difficult. Attempting to compute the cumulated structural damage from various hazards becomes very difficult with these limitations. This paper describes the implementation of a probabilistic framework that includes effects such as structural weakening due to a first-acting hazard in the analysis of structural damage when contemplating subsequent hazards. It also proposes the formulation of damage scales tailored to assess cumulative structural damage from all the hazards involved in the analysis. This allows for the computation of probabilities for final damage states, which can be used in multi-hazard risk analysis or in design with performance objectives. The article explores the application of the proposed framework on the case of structural damage to masonry housing due to earthquakes and earthquake-triggered floods. The particular case concerns an unreinforced masonry house located behind a levee.