Mojtaba HARATI - MSc student, Sharif University of Technology, Tehran
Hassan MOGHADDAM - Professor, Sharif University of Technology, Tehran,

The observed response of medium rise buildings during sever earthquakes worldwide has indicated that RC buildings with shear walls behave considerably better than other buildings. The conviction that shear walls are inherently brittle still prevails amongst engineers, and therefore, they usually prefer to choose moment resisting RC frames without shear walls. In this study, a number of RC frames, with and without shear walls are designed in accordance with the seismic codes, and are then subjected to an assemble of severe earthquakes. The results of time history nonlinear analyses of these models are then used to investigate the effect of the presence of shear walls within the framework of performance based design. It is concluded that in general the presence of shear walls results in a significant decrease in the seismic deformation demand. This includes the plastic rotations in RC columns and beams as well as the inter story drifts. Consequently, it is concluded that the presence of shear walls generally increases the safety of medium rise RC frames within the assessment framework of performance based design codes such as ASCE41 (2006).