SEISMIC FRAGILITY ESTIMATION UNDER ORTHOGONAL EARTHQUAKE EXCITATIONS

Estimation of fragility functions using dynamic structural analysis is an important step in a number of seismic assessment procedures. This paper discusses the multicomponent seismic fragility curves based on beta distribution by considering the Iran–specific characteristics to manage the earthquake risk in the region. The seismic design of low- and mid-rise RC-MRFs are carried out according to the Iranian Code of Practice for Seismic Resistant Design of Buildings (Standard No. 2800), and the analytical models are formed accordingly in ZEUS-NL platform. A new optimal intensity measure (IM) called (Sa, avg) is used to obtain reliable fragility–based database for earthquake damage and loss estimation of RC buildings stock. It is observed that the presence of vertical component of the strong earthquake excitation significantly affects the response of RC-MRFs and including this component simultaneous to horizontal components in the analysis is highly recommended for reliable seismic assessment of RC structures.