Predicting ductility demands on reinforced concrete moment-resisting frames for moderate seismicity

The seismic responses of existing reinforced concrete-framed buildings that are primarily designed and detailed to resist onerous combinations of gravity and wind loads are simulated for the conditions of moderate seis micity. A procedure is established for relating the non-seismic and seismic behaviours of structures. By using the proposed procedure, the theoretical curvature ductility demands of ordinary reinforced concrete moment-resisting frames can be evaluated. It has been shown that shear response of the frames due to earthquakes is dominant and adopted as a basis for estimating ductility demands. It is concluded that for low-rise ordinary moment-resisting trained buildings in regions liable to low or moderate sesimicity, the reduction factor suggested in the 1997 UBC might not be appropriate for use in the seismic analysis of these structures. Copyright (c) 2005 John Wiley & Sons, Ltd