The investigation of beam irregularity under earthquake effects

The fact that our country is on the dangerous and risky earthquake belt and the earthquakes result in loss of life and properties necessitate that buildings must be durable and safe against the earthquakes and indicate that every detail is important in planning and building processes. When destructive earthquakes are investigated it is frequently seen the occurrences of beam discontinuities and irregularities in structures. The horizontal irregularities are a frequent situation observed in buildings of the country in earthquake-prone zones due to adding stories in buildings. This situation leads vertical load bearings to remain in interior connections and cause beam joints to be slid over the connections, because of aesthetic concerns, and consequently, to be completed the frame. In this study, the building models with frame and shear wall- frame structures having beam discontinuities due to adding stories were analyzed by "Regulations for the Buildings in Earthquake Zones" using Mode Superposition Method. In this respect, the structures with 4,6, and 8-story in frame models and 8,10, and 12- story buildings in shear wall-frame models were examined by four different cases according to the same story (regular, console, console and irregular facade, and irregular). As a result a total of 24 models were used. The differences were compared by regularities and irregularities, first vibration period values, displacements, interstory drift, secondary rate effects, increases of moments and cutoff values in elements of the load-bearing system. Moreover, 8-story frame model and shear-wall frame model were compared and suggestions were proposed relating to architectural concerns leading to horizontal irregularities.