Earthquake ductility and overstrength in residential structures

This paper reviews aspects of current design procedures for seismic design of structures, and specifically examines their relevance to the design of l ight framed residential buildings under earthquake loading. The significanc e of the various structural contributions made by the components of cold fo rmed steel framed residential structures subjected to earthquake induced lo adings has been investigated. This is a common form of residential construc tion worldwide. Particular attention is given to aspects related to ductili ty and overstrength, the latter arising principally from the contributions of the designated "non-stntctural" components. Based on both analytical and experimental data obtained from research investigations on steel framed re sidential structures, typical ranges of the ductility reduction factor and overstrength ratios are determined. It is concluded that the latter paramet er has a very significant influence on the seismic design of such structure s. Although the numerical ranges for the inelastic seismic parameters given in this paper were obtained for Australian houses, the concepts and the hi ghlighted aspects of seismic design methodology are more widely applicable.