Post-earthquake safety assessment of schools after the 2016 Ecuador M7.8 earthquake

Abstract

The 2016 Muisne earthquake generated significant structural damage especially along the coast of Ecuador. Tests of concrete and reinforcing bars taken from collapsed buildings aided at assessing the impact of materials properties on the behavior of buildings. The paper describes the statistics of damage sustained by schools following the ATC-20 scheme. A set of statistics are developed describing the scaling of damage with distance and PGA. The analyses showed that 30% of the buildings surrounding schools performed “Better” than them, and approximately 33% performed “Worse” than them. For those schools tagged under RESTRICTED USE and with UNSAFE placards, 44% of the surrounding buildings behave “Better” than them, and only 16% behaved “Worse”, indicating the need for a strong public policy to reduce vulnerability of school in Ecuador. Georeferenced data allow a spatial cross-correlation of different levels of damage observed with the ground motion intensity. This information may serve as benchmark for calibration of seismic risk models, and for post-earthquake risk comparison. Furthermore, regional seismic risk assessment may be calibrated with the results of the spatial cross-correlation analyses presented.