Esmaeel IZADI Z. - Ph.D. Student, IIEES, Tehran, Iran
Abdolreza S. MOGHADAM - Assistant Professor, IIEES, Tehran, Iran

In this study the effect of different mass eccentricity scenarios on the dynamic torsional behavior of an 8-story RC moment resistant build ing has been investigated. Firstly, to determin e the range of the mass moment inertia (MMI) variation due to different mass distribution scenarios, three d ifferent scenarios which produce eccentricity were consider ed. These scenarios were applied to the plan of prototype structure and expressions were established to correlate MMI and mass eccentricity in each scenario. Result shows for slight eccentricities the variation of the MMI is negligible but as eccentricity is increased the range of the variation is extended.At the second part of this stu dy, 8-Story RC moment resistant building was designed according to the Iranian seismic code (Standard No. 2800, 3rd Edition). Sensitivity analyses based o n finite element method and inelastic time history analysis h ave been carried out for determining the effects of MMI on the torsional response of the structure.The effects of the variation of MMI on the torsional respo nse of the structure at 2 level of mass eccentricity including slight and severe is investigated and described in detail.

Seismic, Torsional Res ponse, Asymmetric, Mass Moment of Inertia, RC Building