In order to protect existing structure against probable damages in coming earthquakes, and also, in order to expand buildings or to change their applications, studying present conditions of structures and making them resistant against earthquake (if required) are necessary. Steel shear wall was considered as a lateral load carrying member in 1907s. Steel shear wall was used in buildings such as Nippon steel building in Tokyo and Sylmar building in Lose Angeles for the first time. Many experimental and theoretical studying has been done on steel shear walls. But, only in Canada building code (CAS, 1994) a discrete section is devoted to steel shear walls. Among methods of designing structures against earthquake, designing based on performance levels has been taken into consideration in building codes such as ATC40, FEMA273, and FEMA274 because of considering inelastic behavior of structures. Designing based on performance levels is used in the improvement code of Iran, too. Capacity spectrum method and nonlinear static method (NSP) is one of the proposed methods by the improvement code of Iran for making existing weak structures resistant against earthquake. In this paper, earthquake-resistance of weak steel moment frame structures with steel shear walls, cross and chevron braces, are compared with each other using performance levels and capacity spectrum method. SAP and ANSYS soft wares will be used for modeling and analysis.

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