The 7.7 and 7.6 magnitude earthquakes that occurred on February 6, 2023, are called the disaster of the century and caused serious destruction in 11 provinces in Turkey. It was observed that various buildings that collapsed were heavily damaged and had torsional irregularities. This study aims to present in detail all architectural design faults that cause torsional irregularity.
Torsional irregularity in the Turkey Building Earthquake Regulations 2018 (TBDY 2018) and different earthquake codes in other countries will be presented. Then, all problems causing torsion irregularities and suggested solutions will be presented. Finally, a simple square-shaped building will be analysed using different asymmetrical structural members, and the torsional coefficients will be evaluated.
Many factors cause torsional irregularity, such as complex forms, the position of floor openings, insufficient and improper design of structural elements and the differences in stiffness between floors. The numerical analysis revealed that the asymmetric structural system had a significant effect on the torsional irregularity even in building models with simple forms. The torsion coefficients of the building increased from the ground storey to the top storey, with the highest value being 2.65.
In the study, all design factors that cause torsional irregularity, which plays a leading role in heavy destruction in earthquakes, and the measures that can be taken against these factors and alternative solutions are presented in detail.
