Iran Seismic Design Code Evaluation Through Comparison with NZS 1170.5 and a Critical Look at its Directivity Effects Implementation

Document Type : Research Article


School of Civil Engineering, Iran University of Science and Technology, Tehran, Iran


This paper intends to evaluate the existing Iran seismic design code (standard No. 2800) through a comparison process with those of New Zealand seismic code (NZS-1170.5) due to their apparent shape similarity of spectral accelerations being in two parts form. Both standards represent the seismic hazard level of ten percent chance in fifty years. The evaluations made are: the basic design acceleration (A) (in 2800), and the hazard factor (Z) (in NZS), the constant acceleration and constant maximum velocity period ranges of the two spectral shape forms on the four types of site soil conditions, and the approach of implementing the directivity effects by representative parameters, [N(T), in 2800] and [N(D,T), in NZS]. The 2800’s spectral accelerations on the four soil types including the FD-pulses are qualitatively evaluated through hazard-based FD-pulse method. The quantitative results of this study expose that the existing 2800 s’ spectral accelerations need to be increased at relatively small period ranges of 2 s while be decreased at the period ranges longer than 2 s. In brief conclusion, the required design spectral accelerations for buildings which currently are widely constructed in near field sites, are smaller than those of the rationale hazard-based values.


Main Subjects

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