A method to calculate spectral shape factor

Abstract

A method to calculate spectral shape factor (SSF) is proposed which permits the calculation of individual structure. The proposed algorithm efficiently relates the 50th percentile collapse capacity of the given structure to the spectral amplitudes of the rare events. The traditional target epsilon and the conditional mean spectrum are used to estimate the collapse capacity given the hazard level. The process of calculating SSF including the general ground motion set presented in FEMA P695 are performed by the developed MATLAB code. The OPENSEES software is used for dynamic analysis of the structure using the incremental dynamic analysis method. The two reinforced concrete special moment frame structures having eight and four stories previously designed and used by Haselton are tested. The results are compared with those of the FEMA P695 and Haselton ending up with smaller SSF values. The result of this study is useful for calculating the structural collapse margin ratio and risk-targeted specific site response spectrum.

Keywords:

• collapse capacity
• fragility curve
• IDA
• spectral shape factor
• hazard level

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Open System for earthquake engineering simulation.