Application of a Stochastic Method for the Development of Earthquake Damage Scenarios: Elat Test Case

This article summarizes the work done over the last 10 years regarding the development of a new approach for earthquake damage scenarios. The development process was tested in Elat, Israel, and involved microzoning of site effects across the city, monitoring of dynamic characteristics of buildings in Elat, creating databases of the building inventory in the city and its population distribution, and preparing a computerized GIS based application. The new approach is based on comparing the designed spectral acceleration level at the resonance frequency of a building with respect to the predicted level for the same building and for a given earthquake. The predicted spectral accelerations are computed by using the stochastic simulation technique of the ground motion spectrum, stochastic (Monte Carlo) simulations of an earthquake, and the local site response function. The first test scenarios have demonstrated the applicability of the new approach that was also put to the test during the 22 November, 1995 earthquake (Mw = 7.1) in the Gulf of Elat/Aqaba. The predicted consequences of that earthquake, presented in scientific meetings a few months before the earthquake occurred, agree well with later observations in Elat, Israel. We also concluded that the "classical" approach, which is based on seismic intensity attenuation functions, yields exaggerated damage scenarios.