A method for determining the behaviour factor of moment-resisting steel frames with semi-rigid connections

In this paper, firstly, existing methods for determining the behaviour factor of moment-resisting steel frames and their range of applicability for multi-degree-of-freedom frames are reviewed. Modifications of this factor for multi-degree-of-freedom moment-resisting steel frames are then indicated. Necessary modifications in determining the behaviour factor of frames involve the period and the base shear distribution factor for a given earthquake loading code. The effects of storeys, spans and connections of frames on the behaviour factor were considered over ranges of values for these factors for frames with semi-rigid connections up to five spans and ten storeys. On the basis of the results, new relationships for the period and the behaviour factor of moment-resisting steel frames with semi-rigid connections as a function of the main geometric parameters of the frame are presented.