An Earthquake Loss Estimation Methodology for Buildings Based on ATC-13 and ATC-21

Abstract

A survey of the seismic hazards for about 30,000 nonresidential buildings in Portland, Oregon was conducted, and an earthquake damage and loss estimation model was developed. To conduct the buildings survey, ATC-21's Rapid Screening Procedure was used. For each building the data included: address, year built, area, number of stories, building name, use, occupancy type, estimated range of number of people, nonstructural falling hazards, building type, and performance modifiers such as soft story and torsion. Soil data were provided by the Earthquake Hazard Maps published by the Oregon Department of Geology and Mineral Industries. The algorithm set up on the GIS was to compute the structural score based on ATC-21 score, modify the score based on the geologic condition of the site, and finally, compute the damage. The proposed loss estimation model is based on ATC-13, and the scoring system developed by ATC-21. The results are in terms of percent (or dollar) damage to buildings in the survey and loss of life and serious injuries.