Analysis of different cross-frame placements to enhance torsional irregular buildings against structural failure under earthquake bidirectional loadings: A case study

Abstract

Cross bracing frames (CFs) are employed as traditional passive energy dissipating devices, which are placed into the moment-resisting frames of the Benchmark building picked for analysis purposes. These devices are widely used, easy to construct, and inexpensive to contribute better seismic protection for existing and new buildings than complex control systems like active/passive Tuned Mass Dampers (TMDs) and so on. Therefore, in this research, the best three-predetermined CFs placements are selected. The time history analyses are made under bi-directional seismic loads such as two orthogonal excitations of El Centro in 1940, North-Ridge in 1994, and Kocaeli, Turkey in 1999. In conclusion, obtained results find out that while CFs placements into the structure can be significantly eliminating the eccentricity in the structure plan by dissipating especially torsional responses (approximately between 30% and 50% decrease) with a right engineering design perspective like Case 3, they cannot be successful enough to reduce the torsional responses without the right design vision such as Case 1 and Case 2. Therefore, Integrating CFs placements to the structure for minimizing the structural response is not always comprehensive to make the structure durability against torsional irregularity unless placed with the right engineering decision