09-10-2014, 02:48 PM
In many multistory buildings with shear walls, the contribution of columns towards resisting lateral loads is small, and such columns are often designed only for the gravity loads ("gravity columns"). However, such columns may loose their gravity load carrying capacity when undergoing lateral displacements under earthquake excitations. In Northridge earthquake of 1994, failures of several buildings were attributed mainly to the collapse of gravity columns. A computer program is developed in this thesis to study the inelastic seismic behaviour of gravity columns under imposed lateral displacements. The program uses a moment-curvature relationship which is obtained from another program (Mandal, 1993) this program is modified somewhat to include a strain hardening stress-strain relationship of steel. A parametric study is carried out to identify the influence of different parameters on the drift capacity of ACI- and IS-designed columns. ACI-designed columns were detailed as per ACI 318-89 (Revision 1992) and for ACI 318-95, while the ISdesigned columns were detailed as per