Evaluation of the seismic hazard of Barcelona and its application to the estimation of the seismic risk of the city

Abstract

In the present work, the main steps used in the probabilistic estimation of the seismic hazard of the city of Barcelona, ​​Spain, are described, and it is mentioned how the hazard was used in the probabilistic estimation of the seismic risk of the city. For comparative purposes, the seismic hazard of Barcelona was estimated both in terms of exceedance rate of the macroseismic intensities, and in terms of exceedance rate of the maximum ground acceleration (PGA). In the estimation, the computer code CRISIS2008 (Ordaz et al., 2008) was used, which is based on the methodology proposed by Cornell (1968) and Esteva (1970). This code incorporates valuable tools that allow estimates of seismic hazards to be made at an important level of detail. According to the results, in Barcelona, ​​the PGA value equal to 85 cm/s2, has an average return period of 475 years. The results obtained in terms of macroseismic intensities, indicate that the intensity that has an average a return period of 475 years corresponds to a value between VI and VII. The seismic hazard curves in terms of macroseismic exceedance rates were obtained with the aim of being used in the estimation of the seismic risk of the city by means of the probabilistic method of vulnerability indices (Aguilar, 2011). According to the results, in the city there are buildings with a high level of seismic risk. This is because, despite the fact that Barcelona is located in a zone of low to moderate seismicity, there is a significant percentage of buildings with significantly high levels of seismic vulnerability. The seismic risk curves obtained are expressed in terms of exceedance frequencies of the degrees of seismic damage.