EVALUATING THE EFFECT OF SYMMETRY ON SEISMIC BEHAVIOR OF IRREGULAR BUILDINGS IN PLAN

Different seismic regulations provide different definitions related to irregular criteria in buildings. In addition, these regulations categorize the buildings into two kinds: regular and irregular buildings. Seismic regulations neglect the effect of symmetry on the seismic behavior of irregular buildings as a factor against irregular buildings in plan; therefore, in this paper the effect of symmetry on the behavior of unparallel systems is studied. For this purpose, 6, 10 and 15 storey concrete buildings designed based on Design Regulation of Iran are used. In addition, the conventional software ETABS 9.5.0 and capacity spectral method are used to determine operation point of models. The paper concluded that in ten storey buildings, the wedge-shaped models show critical behavior rather than trapezoidal -shaped, asymmetric models.