Development of Fragility Curves for RC Building

Abstract

Structural elements and structure as whole undergoes varied extent of damage when subjected to seismic hazards. Structure may completely collapse under extreme seismic hazards. Thus, estimation of seismic hazard has been an active area of research now-a-days. Quantification of a seismic hazards offer a stiff challenge to seismic analyst since behaviour of structure beyond elastic limit is required to be measured. Various methods like Non-linear static method (Pushover method), Non-linear Dynamic method (Non-linear Time History method) are mostly adopted. Recently, estimation of seismic hazards through Fragility Curves for particular response parameter has been widely adopted technique due to ease of understanding on seismic hazards. In the present study, seismic hazard estimation for G+4 story Reinforced Concrete (RC) Building is carried out by developing Fragility Curves. Fragility Curves are developed for maximum story displacement and maximum inter-story drift of RC building through two type of seismic analysis methods, namely, Linear Time History analysis and Non-linear static analysis (Pushover method). Apart, comparative study on Fragility Curves of RC building developed using two guidelines ATC-40 and FEMA-440 are also carried out to study improvement of guidelines of later over former. Additionally, performance point for RC building following guidelines of FEMA-440 is obtained using EXCEL programming based spreadsheet against one of the well-established commercial software. It has been found that G+4 story RC building has high probability of exceedance for immediate occupancy for Low PGA values and less probability of exceedance for life safety and collapse prevention. It has been observed from parametric study that Fragility Curves for RC building developed by ATC-40 and FEMA-440 guidelines are identical.