Match Compliance of Conventional Design Codes with Instructions for Seismic Rehabilitation of Buildings in Performance Evaluation of Steel Moment Frames

Today, instructions for seismic rehabilitation of existing buildings are widely used for seismic performance evaluation of existing buildings. Moreover, nonlinear structural analysis methods are permitted for seismic design of new buildings in recent versions of seismic design codes in some countries, such as Iran. Therefore, match compliance of conventional design codes with instructions for seismic rehabilitation of existing buildings is of great importance. On the other hand, four different analysis methods are available in seismic rehabilitation instructions that compatibility of these analysis techniques can be evaluated. In this regard, seismic performance of three buildings with steel moment frames as lateral load resisting system with 4, 8 and 12 stories that were designed previously according to conventional seismic design codes with two levels of ductility (Intermediate and Special) were evaluated using seismic vulnerability assessment instruction in Iran (Code No. 360) by means of four analysis procedures. Analysis results indicate that conventional seismic design codes are more conservative than Code No. 360. In other words, design of steel moment frames with conventional design codes leads to stronger beams and columns. This phenomenon can be due to controlling lateral interstory drift and weak beam-strong column criterion in moment frames that control final design of these structures.