This is a post Loma Prieta earthquake (Oct. 1989) investigation project in learning from this damaging event. The ATC-20 "Procedures for Postearthquake Safety Evaluation of Buildings," published by Applied Technology Council (ATC) on September 19, 1989, were used extensively throughout Northern California to evaluate buildings damaged by the magnitude-7.1 October 17, 1989 Loma Prieta, California, earthquake. The widespread application of the methodology on several thousand buildings by building officials and volunteer structural engineers from throughout the state has provided a rare and ideal opportunity to assess the merits and possible pitfalls of the methodology. Based upon such an experience, this project will conduct a study to review, evaluate, and possibly revise the ATC- 20. The specific objectives are to: (1) document the application of the ATC-20 methodology; (2) conduct a workshop to review, expand, and evaluate this documentation and develop recommendations for improved procedures; (3) develop and publish an addendum to the ATC-20 Report containing a summary of the Loma Prieta earthquake experience, a summary of the project workshop findings, additional instructions and clarifications for "difficult to determine" posting situations, and a recommended management program for local building officials; (4) revise and re-publish, if necessary, the ATC-20 Report and ATC-20-1 Field Manual; and (5) conduct training seminars that include an overview of the Loma Prieta experience. This effort will enhance the methodology for safety evaluation of buildings following an earthquake.
