Methodology for Integrating a Structural System in Risk Target Ground Motion: Case study, Special Concrete Moment Frames Designed According to Iranian Seismic Code

American seismic code utilizes Maximum Credible Earthquake (MCE R) with uniform Risk in order to determine design spectral accelerations regardless of the structural system. Thus, it is of interest to suggest a procedure to decide MCE R considering structural systems. The effect of building types can be significant both for new and old buildings. Further, the number of stories and soil condition are crucial elements which seem to have considerable effects on the results. As such, there are different sources of uncertainties in the seismic response of a structure where the values of B (β) and 10% percentile can have a decisive effect on risk targeting. The study suggested a framework to assess uniform risk spectral acceleration in terms of building type. While Iranian seismic code utilizes a different design approach from that of the American one, it is of interest to suggest a procedure to determine the above parameters for concrete frames in Iran.A case study approach was used to represent the proposed method. The area of study included two cities in the north part of Iran. Twelve special concrete moment frames were designed in 5-, 8-, and 12-story considering four soil conditions. Uniform risk and uniform hazard spectral acceleration were determined. The collapse probability of structures was between 0.4 and 1.6. Furthermore, uniform risk spectral acceleration was larger than uniform hazard acceleration at all stations regardless of their soil types and number of stories. For the structures of this research, confidence interval had greater influence on than B value. Further, soil class affected the more considerably than the number of stories did.

کلیدواژه ها:

Seismic hazard ، Uniform risk ، Uniform hazard ، Iran