3rd Croatian Conference on Earthquake Engineering 3CroCEE

The focus of this research is to determine the impact of structural eccentricity on the seismic behavior of torsionally sensitive structures. To achieve this, two groups of single-story structural models with different levels of irregularity were analyzed. The dimensions of the structures at the base are 6 m x 5 m, with a story height of 3 m. The total external load on each structure is 300 kN. In the first group of structures, the center of mass was shifted by redistributing the load over a smaller area. In the second group, the center of stiffness was altered by increasing the cross-sectional dimensions of the columns on one side of the structure. Analyses were conducted for structural eccentricity ranging from 5% to 30%.
In accordance with the criteria provided in Eurocode 8 and ASCE 7-22, the torsional regularity of the analyzed structures was assessed. For the same value of eccentricity, a comparison of the levels of irregularity between the two groups was made. Through the results obtained from the nonlinear static analysis, a relationship between the level of irregularity and the level of damage was established. Additionally, an evaluation of the torsional irregularity criteria in both regulations was conducted, highlighting the advantages and disadvantages of each approach.