Rapid assessment of seismic demand in existing building structures

Seismic assessment of building structures can be a very involved process. This paper presents a simplified and rational manual procedure for rapid predictions of maximum inter‐storey drift demand in tall buildings, which does not require frame analysis nor finite element analysis to be carried out and can be expedited by the use of a spreadsheet program. The methodology comprises a series of stages, beginning with the development of an elastic design response spectrum (or a uniform hazard spectrum) for specifying the level of seismic hazard, followed by the inclusion of a site‐specific factor that represents the effects of soil amplification. The maximum seismic inter‐storey drift demand of the building is then predicted from the displacement response spectrum for a given height and the estimated lateral natural periods of the building. The proposed manual procedure can be further developed to cater for limited ductility demand behaviour in the building. The predicted drift demand is an important indicator of potential seismic damage (risk), and may be utilized for the rapid assessment of damage and loss (cost) for considered earthquake scenarios.