dependency of the accidental torsion building response on both live-to-dead load ratio and material stiffness variation

Numerical simulations were performed in this work to assess the impact of the ratio of live-to-dead load (ρ) and the stiffness variability of the constitutive materials on the accidental torsional response of buildings. three values of ρ (0.2, 0.5 and 0.8) and two materials (reinforced concrete and steel) were studied. story drifts and ductility demands were the main structural response parameters analyzed to evaluate the significance of both variables. six structural models, representative of frame buildings with different lateral vibration periods (0.25 to 1.5 s), were subjected to five earthquake ground motions recorded on firm soils. with the monte carlo method, the intensity and location of the live load, as well as the flexural stiffness of the structural members, were randomly varied to simulate building cases with accidental torsion. according to the results, the effect of the live-to-dead load ratio (ρ) on the torsional response is more significant than that of the material stiffness variation. for both materials, the maximum torsion response for ρ = 0.8 resulted 66% greater than that for ρ = 0.2. for both materials and considering all earthquakes and structural models, the increase in the average peak accidental torsional response for ρ = 0.8 was approximately 20% greater than that for ρ = 0.2. these results corroborate that the accidental torsional response of buildings increases in proportion to ρ. discrimination between concrete and steel buildings was not significant. © the author(s), under exclusive licence to the iran university of science and technology 2024.