چكيده به لاتين
Abstract:
One of the most important parameters being used in equivalent lateral force procedure (ELF) to estimate seismic force is response modification factor. This coefficient represents the effect of properties such as over strength, redundancy and ductility of structure. In seismic loading codes, the value of response modification factor only depends on the type of lateral force resisting system. But there are factors that may significantly affect R factor of structure, i.e. period and seismic effective mass of building. In the present study reinforced concrete SMRF structures are designed and analyzed by spectral dynamic method based on standard 2800 and INBC chapter 9 provisions, then they are evaluated by means of nonlinear static push-over analysis, and finally R factor of structures are determined. In modeling, in order to consider the effects of period, structures are used with 3, 7, 10, 14 stories, and to establish the effects of seismic effective mass, residential and shopping center occupancies are used. According to the results of this study, R factor changes by the variation of the period of structure, i.e. except 3-store building, the R factor increases with increment of the period for other structures. Also for different occupancies, more gravity loads leads to negligible increase of R factor, assuming number of stories and sections are the same. Using of last edition of Iranian design codes, spectral dynamic analysis, choosing RC SMRF structure and paying attention to the effects of period and seismic effective mass on R factor are the innovations of this study.
Keywords: Response modification factor, Time period, Effective seismic mass, Push-over, RC SMRF
