SEISMIC PERFORMANCE ASSESSMENT OF REINFORCED CONCRETE SETBACK BUILDINGS

Abstract

Construction of irregular buildings both in plan and elevation is very common due to space, architectural and functional constraints. However, past earthquakes (the 2001 Bhuj Earthquake, 2011 Sikkim earthquake etc.) demonstrated that irregular buildings are more vulnerable and experienced more damage during seismic excitation. Therefore, before going to design setback buildings, it is very much essential to understand the seismic performance of these buildings. In this paper, an analytical study has been carried out to understand the differences in various responses of setback buildings as compared to regular buildings. To fulfill the objectives reinforced concrete buildings with different storey level like, 3, 5, and 10 storied buildings are considered and for each building seven different setback configurations have been introduced. Accordingly, total 24 numbers, 3D reinforced concrete building models have been designed as per Indian code IS 1893:2002, IS 456:2000 and analyzed using SAP 2000 v (17.2.0). Response spectrum analysis is performed on all the buildings and variation in response quantities such as shear forces, bending moments etc. in different structural element have been assessed by comparing between the regular and setback buildings. This study may help the practicing engineers to improve the understanding about seismic vulnerability of setback buildings.