Probabilistic seismic vulnerability and loss assessment of the residential building stock in Costa Rica

Abstract

This study presents a seismic vulnerability and risk assessment of the residential building stock in Costa Rica. It proposes a new exposure model using housing census data, public construction statistics, and private construction information to quantify and characterize the residential building portfolio. A complete vulnerability catalogue is established by developing fragility functions for the most common building classes and combining them with existing models derived for risk assessment in South America. An existing probabilistic seismic hazard model was implemented within the OpenQuake-engine, and complemented with a simplified site model to account for site effects. Earthquake risk assessment is achieved by means of a probabilistic event-based analysis, which allowed the estimation of several risk metrics. These include average annualized losses at a national scale, disaggregated per building class and administrative regions. The probable maximum losses and exceedance probability curves were generated using a stochastic event set with 100,000 years of events per logic tree branch.