SEISMIC BEHAVIOUR OF OPEN GROUND STOREY REINFORCED CONCRETE BUILDINGS

Abstract

Open ground storey (OGS) buildings are the most common type of building configurations witnessed particularly in the urban areas due to their inherent functional advantages (Viz., basement/underground parking facilities in Apartment and Commercial complexes). These categories of buildings usually referred as soft storey buildings. These configurations have shown poor seismic performance across the world due to sudden drop in stiffness and strength in open ground storey. Several open ground storey buildings have collapsed even during Bhuj earthquake in 2001 emphasising the need to understand its seismic behaviour. This led to special considerations of specification of large design forces in IS1893 part1 for the soft storey compared to the rest of the structure. These considerations increased the shear capacity of weak storey columns to prevent collapse and subsequent loss of life. Hence, the present study is focussed on simulating the open ground storey buildings. Non-linear static analysis (Pushover) is performed using the response spectrum specified in the IS code. Further, the importance of masonry infill wall and its contribution for strengthening the open ground storey is also discussed.