SEISMIC DESIGN PROVISIONS FOR DUCTILE DETAILED REINFORCED CONCRETE STRUCTURES

Abstract

Most seismic design codes allow structure to be designed for lesser force than elastic force, thus allowing structure to damage at appropriate locations. Indian seismic code IS 1893-2002 divides seismic design of structures into three categories; Ordinary moment resisting frame, Intermediate moment resisting frame and Special moment resisting frame. The classification differs based on reinforcement detailing and response reduction factor. It is expected that the performance of ductile detailed building would be better than non ductile detailed building and the capacity shall be more and damage is less compared to non ductile detailed building. This paper compares the performance of structure designed considering non ductile detailing and ductile detailing, in terms of capacity, damage, response reduction factor and drift. As a case study, a 5 storey building designed for Gravity loads as well as lateral load as per IS: 1893-2002 for seismic zone III is considered. Static Non Linear (Pushover) analysis and fragility analysis are performed for estimation of post damage yielding behavior of structure. The change in non linear behaviour of structure based on assumed load patterns in pushover analysis is done. This paper also provides other important conclusions on seismic design provisions, response reduction factor and interstorey drift.