Canadian Journal of Pure & Applied Sciences

Abstract: In this paper the performance of different nonlinear static analysis methods and their accuracy in predicting the seismic response of structures isolated by sliding base isolators has been compared. For this purpose, first,5 and 10-story isolated steel structures with special moment frames located in LA, US were designed according to AISC 360, AISC 341, and ASCE 7 design requirements. In this study, friction pendulum system (FPS) has been used as isolation system. Results of non-linear static pushover analyses of the models with triangular, uniform, and PSC (Protective Systems Committee) load patterns, modal pushover analysis (MPA), and N2 method were compared with the results obtained by nonlinear dynamic time history analysis as a criterion for accuracy in this study. According to the results, it was concluded that in predicting the story shear responses, pushover analysis with triangular load pattern had accurate response compared to other studied methods. Also in predicting floor displacement responses and story drifts, pushover analysis under uniform load pattern, N2, and MPA methods resulted in more accurate responses regarding the other methods. Overall, N2 method had the most accuracy with respect to nonlinear dynamic analysis in predicting story shears, story drifts, floor displacements and maximum hinge rotations in structures isolated by sliding base isolators