Seismic assessment of existing structures by displacement principles

This paper presents a practical method for estimation of the roof and maximum inter-storey drift ratios which can be utilized in the approximate seismic assessment of existing building structures. The height-dependent building models employed can represent the existing buildings of different height which are laterally supported by walls, moment resisting frames or a combination of walls and frames. In the employed macro model, realistic estimations of the distribution of floor lumped masses and height-wise lateral stiffness of existing buildings were considered. Extensive dynamic analyses were conducted to investigate the generic modal displacement hypothesis and to model drift parameters of interest considering the higher mode effects. The suggested drift predictors has the capability to be used in conjunction with site specific spectral displacement for constructing the drift spectra which is a plot of the roof and maximum inter-storey drift ratios versus building first mode period or height