As a vast part of the structures, the reinforced concrete structures can provide very optimal buildings in case of being designed and implemented based on accurate calculations and ductility relations. These structures might be in need of reinforcement for various reasons, including designing and executive errors as well as procedural variations. In order to exactly evaluate such structures and determine the extent to which they may fail, the use of the failure indices that have been dealt with a lot during the recent decades can be a promising solution. The present study aims at studying the vulnerability indices of the reinforced concrete moment-resisting frames retrofitted with steel braces. The frames studied herein are in match with the criteria mentioned in the tenth chapter of the building regulations and 2800 guidelines with the buildings in which they are to be used featuring intermediate importance. In terms of the evaluating the vulnerability indices, the results indicated that the concrete moment-resisting frames are highly vulnerable when subjected to earthquake waves and they undergo a lot of displacement, movement and crushes. However, they would exhibit proper seismic behaviors if they are improved and retrofitted with steel braces. It has to be pointed out that a structure’s performance status is specified in respect to its failure index.
