Study on Effect of Zone on Magnification Factor for Open Ground Storey Buildings

Paper Topic :

Structural Engineering

Author Name :

Amol Karemore

Abstract :

Open ground storey (also known as soft storey) buildings are commonly used from past few years. Mostly they provide parking areas in soft storey. These types of buildings are generally collapse during earthquake due to soft storey effect. Displacement induced in the first floor is very large. This large displacement is due to yielding large curvature open ground storey building. The bending moments and shear forces in these columns are also magnified accordingly as compared to a bare frame building. Due to presence of infill in the frame alters the behavior of building under lateral load. In industrial practice the stiffness of infill is ignore for analysis of frame building. Engineers believe that analysis without considering infill stiffness leads to a conservative design. Hence, the modeling of infill in the seismic analysis of framed buildings is imperative. Indian Standard IS 1893: 2002 allows analysis of open first storey buildings without considering infill stiffness but with a multiplication factor 2.5 in compensation for the stiffness discontinuity. As per the code the columns and beams of the open ground storey are to be designed for 2.5 times the storey shears and moments calculated under seismic loads of bare frames (i.e., without considering the infill stiffness).

Download Article