COMPARATIVE STUDY OF RESPONSE OF IRREGULAR STRUCTURES AND EFFECT OF SHEAR WALLS ON IRREGULAR BUILDINGS

A structure is “regular” if the distribution of its mass, strength, and stiffness is such that it will sway in a uniform manner when subjected to ground shaking – that is, the lateral movement in each storey and on each side of the structure will be about the same. Regular building configurations are almost symmetrical (in plan and elevation) about the axis and have uniform distribution of the lateral force-resisting structure such that, it provides a continuous load path for both gravity and lateral loads. A building with absence of symmetry and has discontinuity in geometry, mass or load resisting elements is called irregular. These irregularities may cause interruption of force flow and stress concentrations. Asymmetrical arrangements of mass and stiffness of elements may cause a large torsional force because the centre of mass does not coincide with the centre of rigidity. In this study L-shape plan of G+7 storey reinforced concrete building have been selected. The models are analyzed in two phases, in First Phase the building is analyzed without shear walls and soft-storey in Ground floor and Second Phase the same building is analyzed with shear walls and having soft-storey in Ground floor. In the Second Phase also the shear walls are added to the model in two different cases, to study the best location of shear walls in the building.The models are analyzed by STAAD. Pro V8i SS6 software using IBC-2012(9) code (International building code 2012), by Linear Static Method. As the IBC-2012 Draft Code (Afghanistan Building Code-2012) is used for structures in Afghanistan, so the IBC-2012 code has been sleeted for analysis. The aim of this paper is to study the effect of shear walls on soft-storey and compare the response of irregular building having shear walls with irregular buildings without shear walls. The results are summarized on basis of the response of building.