DYNAMIC ANALYSIS OF G+13 STOREY RC BUILDING HAVING VERTICAL (MASS & STIFFNESS) IRREGULARITIES

Weight (mass) irregularity is defined where the effective mass of any story is more than 150% of the effective mass of an adjacent story and per Section 7.1 of 1S-1893-2002, “Mass irregularity shall be considered to exist, where the seismic weight of any storey is more than 200% of that of its adjacent storeys Generally, roof is lighter than the floor below is not to be considered.Stiffness-soft storey irregularity is defined, if a story lateral stiffness is less than 70% of the story above or less than 80% of the average stiffness of the three stories above.For analysis of models G+13 storey reinforced concrete buildings is selected, with considering mass and stiffness irregularities along the height of building. In first case the selected G+13 storey RC building is analyzed with considering mass irregularities. The heavy mass is added to the building at three different locations along the height of building. In second case the same selected G+13 storey RC building is analyzed with considering stiffness irregularities instead of mass irregularities, at three different locations along the height of building. The models are analyzed using IS-1893-2002 & IBC-2012 codes bylinear dynamic(Time History) method in STAAD Pro softwareand Bhuj Earthquake Time History (26 January 2001), Ahmedabad Station data is used in the analysis procedure.The aim of the research is to study the effect of mass and stiffness irregularities in different location along the height of building and compare the results of IS-1893-2002 & IBC-2012 codes.