HAMZEH SHAKIB - Assistant Professor, Department of Civil Engg., T.M.U., Tehran
NASROLLAH AMINI - Graduate Student, Department of Civil Engg., T.M.U., Tehran

In order to evaluate the torsional provisions of the Iranian seismic building code this study is carried out. First of all, the design eccentricity of some important seismic building codes are compared with the design eccentricity given by the Iranian seismic building code. Then, the design eccentricity is obtained by an acceptable dynamic analysis. Further, by considering giuplicity and contribution of important structural parameters an expression of design eccentricity is proposed for the Iranian seismic building code.