Fragility Analysis of Building Frames with Buckling Resistance Braces Using Incremental Dynamic Analysis Based on Pushover Curve

In this study, the probabilistic seismic performance of building frames with non-buckling braces has been investigated using the incremental dynamic analysis method based on the pushover curve obtained from the non-linear static analysis. The incremental dynamic analysis method is known as one of the accurate analysis methods for estimating the lateral seismic collapse capacity of structures, but it is costly due to the need for nonlinear dynamic analyzes in a record-by-record approach. In this article, without performing such time-consuming analyzes of incremental dynamic method, with proper accuracy and using the results of non-linear static analysis and applying an algorithm to extract the summary of incremental dynamic analysis curves from the results of non-linear static analysis, incremental dynamic analysis curves have been extracted in quantiles of 16, 50, and 84%, and in the following, after obtaining the statistical characteristics of the earthquake intensity at the thresholds of the damage parameter such as the relative displacement of the floor, the seismic evaluation of the studied structures at different performance levels has been carried out in a probabilistic approach and with the drawing of fragility curves. The results of the average acceleration in the performance levels of life safety (i.e., in the risk level of earthquakes with a return period of 475 years) 1.30 g, 0.77 g, 0.92 g, and 0.60 g, and the threshold of collapse (i.e., in the risk level Earthquakes with a return period of 2475 years) are 1.56 g, 0.96 g, 1.15 g, and 0.75 g for frames of 4, 8, 12, and 16 floors, respectively. Therefore, the results show that only in the 4-story frame, the intended performance for seismic risk levels has been provided, and other frames have not been able to provide the required performance criteria.