Seismic Response of Open Ground Multi-Storey Building Retrofitted with Infill Wall, Shear Wall and Steel Bracing.

Most of recent constructed buildings have a common feature, the ground storey remains open, and there are no partition walls in ground storey. It is highly flexible in the ground storey, the relative horizontal displacement in the ground storey is much higher than what each of the storeys above it has. This highly flexible ground storey is also called soft storey. Soft storey (relatively weak ground storey) building shows a higher chance of collapsing during earthquake because of flexibility. The total horizontal force in ground storey is much higher than its upper storeys. Higher flexibility directly results in higher displacement in lower floors of such framed buildings. In such buildings due to open storey the moments & shear force in columns is on higher side as compared to other framed buildings. As the study suggest it is highly risky and need at most care in designing such buildings with open ground storey. For all the new RC frame buildings it is recommended that there should be no such sudden reduction in stiffness. 4 To reduce such effect it is recommended to have masonry walls or RC shear walls in ground storey. Infill helps in achieving a more flexible structure, and gives a strut like action between columns and beams (force is transferred from one node to another). In the present study the high rise building is studied by considering presence of infill walls and shear wall. The response spectrum analysis is performed for building with infill arrangement and RC shear wall on open ground storey. 1