PERFORMANCE BASED SEISMIC DESIGN OF REINFORCED CONCRETE BUILDING FRAMES

Abstract

Buildings and other structures must be designed to perform satisfactorily to

withstand earthquake, provide safety to human lives, and to minimize the

economic losses from the damages, if any. Current code-prescriptive forcebased

design intends to provide strength and ductility to structures for life

safety, but actual performance is never assessed. Structures designed with a

code-based approach experienced extensive damage leading to enormous

economic loss and high repairing costs in the past earthquakes (e.g., 1994

Northridge and 1995 Kobe earthquake). With a view to enhancing safety and

reducing damage, i.e., emphasizing the performance of structures accelerated

the development of performance-based seismic design. This study aims at

designing reinforced concrete building frames following performance-based

earthquake engineering approach. An archetype eight storied RC building has

been selected and a frame has been analyzed and designed following the

seismic design approach of the BNBC 2020. Nonlinear time history analyses

using suitable earthquake ground motion records have been performed to

assess the performance of the code designed building frame. The selected

ground motions have been matched with acceleration response spectra of

required earthquake hazard levels to check the selected performance objectives.

Story drift, an indicator of damage, has been selected as an engineering demand

parameter to quantify performance. Then, the frame has been designed using

the performance based seismic design approach meeting the selected

performance objectives. Finally, the effects of base flexibility on the responses of

the building in force-based and performance-based design approaches have

also been assessed. The present study will help designers, owners, and

stakeholders to make intelligent decisions in designing new or strengthening

existing buildings to achieve the required performance of the structures.