SEISMIC ANALYSIS OF MULTI-STOREY REINFORCED CONCRETE BUILDINGS HAVING TORSIONAL IRREGULARITY

Adarsh A, Rajeeva S V

Abstract: Damage reports on recent earthquakes have indicated that torsional motions often cause significant damage to buildings, at times leading to their collapse. The objective of this work aimed a better understanding of the torsional behavior of building systems. In this analysis both symmetric and asymmetric structures with plan irregularity are compared. Symmetric structures have centre of mass coinciding with the centre of rigidity and the torsion effect in such structures occurs out of accidental eccentricity whereas in asymmetric structures have irregular distribution of mass and stiffness and its centre of mass and centre of rigidity do not coincide and hence causes the torsional effect on the structures which is one of the most important factor influencing the seismic damage of the structure. To assess the torsional effect on the structures in the present study 5 types of structures having same different perimeter area are considered and strengthened by introduction of shear wall cores. A simple linear comparison based on eccentricity is also carried out for the structures. Structures with asymmetric distribution of mass and stiffness undergoes torsional motions during earthquake. The performance of the structures is assessed as per the procedure prescribe in IS 1893:2002. Equivalent static and response spectrum methods are considered for the analysis of the structure. The analysis of the structural models is carried out using ETABS 2015 software.

Keywords: Shear wall, Displacement, Drift, Equivalent static method, Response spectrum method

DOI: https://doi.org/10.15623/ijret.2017.0609010