Direct displacement approach for seismic drift prediction
Given the shortcomings evident in the standard force-based (FB) procedure widely employed for seismic design and assessment, an alternative procedure based directly on displacement is proposed in this paper. Significantly, in the proposed drift model the effects of building height, deflection shape and higher mode contributions are accounted for by a series of scaling factors. These factors have been developed from extensive parametric studies along with field measurements, both of which have been reported herein. The proposed prediction model enables accurate determination of the maximum inter-storey drift angle qmax in a multi-storey building. The maximum drift angle is an important indicator of earthquake-induced damage to both structural and non-structural components, especially in tall buildings where higher vibration modes may contribute significantly to drift demand.