Effectiveness of Seismic Retrofit for Existing Concrete Buildings using Nonlinear Static-Analysis

In the present study, the effectiveness of the various retrofit methods for concrete structures are investigated and compared. Six methods has been presented and three most used methods; i.e. Steel Jacket, Steel Bracing and Shear Wall; are selected for further comparison and studies. The behavior of reinforced concrete structures is assessed using nonlinear static analysis and the capacities as well as demand are calculated for the target performance level. For this purpose, a weak five story concrete structure was utilized. Due to its weak design, it was recognized that the building needs re-design and retrofitting. The performances of the structure before and after retrofit by three proposed methods were compared with each other. Results of numerical Simulations show that all three retrofit methods are effective in reduction of lateral displacements, increasing of ductility and improvement of the structural capacity. However, steel bracing and shear wall are most effective for reduction of lateral displacements.