Most major United States metropolitan areas possess a large inventory of unreinforced masonry (URM) building structures. In seismic prone regions, such buildings represent serious threats to the public safety. The main objective of this project is to study the effectiveness and special problems of using post- tensioned steel braces for the purpose of upgrading URM building structures for seismic hazard mitigation. Such a technique overcomes a lot of problems associated with traditional bracing schemes and holds much promise for broad applications in seismic rehabilitation. One major obstacle in the development of seismic rehabilitation techniques is the lack of a consensus analytical procedure for evaluating the seismic resistance of URM building structures. Currently a unified methodology using the so-called "Strut-Analogy" method development will be used as a tool for the analytical modeling for the URM buildings. The combined URM and post-tensioned system will then be analyzed to assess this technique's effectiveness. This project is supported under the NSF Research Initiative No. 92-28 on "Repair and Rehabilitation Research for Seismic Resistance of Structures."
