A simplified method for evaluation of seismic displacement of reinforced concrete frame buildings

Current seismic design requirements specify lateral displacement or story drift limits to be compared with calculated results from structural analysis. The lateral displacements for different types of buildings are usually predicted through commercial structural software, which takes much computational time at the beginning of the structural design. In this research, a simplified equation is proposed to calculate lateral displacements of buildings under lateral loads with different distributions. The equation is developed to quickly predict the elastic and inelastic building displacements during preliminary design of new buildings or seismic assessment of existing buildings without performing expensive dynamic time history analyses using software. The proposed method is based on elastic beam theory and is compared with similar ASCE (American Society of Civil Engineers) 7-10 procedures. The accuracy of the proposed method is validated by the elastic and inelastic analysis using 2-D (two dimensional) and 3-D (three dimensional) frame buildings. Additionally, the equation is used to determine inelastic story displacements of ordinary, intermediate and special moment frames, and coefficient used to compute the inelastic story displacement according to the proposed equation are recommended in this study.