Evaluación del riesgo sísmico de edificaciones existentes en la Isla Isabela, Galápagos

Abstract

The aim of this paper is to evaluate the seismic risk of 50 typical buildings located on Isabela Island in order to measure their vulnerability with the application of two seismic vulnerability methodologies of existing buildings adapted to Ecuador and its application to Isabela Island, based on proposals of the Federal Emergency Management Agency and the Venezuelan Seismological Research Foundation. Two field data collection forms were prepared to gather data about design and construction of structural and non-structural elements; furthermore, considering their current irregularities. An “S” score and different risk, vulnerability, seismic hazard and prioritization indexes are defined to determine vulnerability ranges of the 50 inspected buildings.
This research is carried out within the framework of the recent activation of the Sierra Negra volcano and the seismic activity of the Galapagos Islands, which would place vulnerable buildings in eminent seismic risk. It was obtained that 34% of them have very high vulnerability and 28% are high. These indexes are also compared with the indexes that would be obtained with some buildings affected during Bahía and Pedernales Earthquakes to calibrate such data. The prioritization indexes will support administrative and technical measures that would allow to guide a more detailed structural evaluation in order to deal with a seismic rehabilitation of the buildings with the highest priority.