Negative Aspects Regarding the Ductile Seismic Design Concept of the Pure Moment Resisting (MR) Reinforced Concrete (RC) Frame Systems (A Theoretical Study)

Seismic activity in the last two decades validate the urgent improvement requirement of the ductile seismic design concept for the MR RC frame structures. This necesity of improvement comes from the unfavorable recorded seismic response of the MR RC frame structures required to on-site seismic actions. The same observations and conclusions (regarding the soft storey (Ground Floor (GF) or Current Floor (CF)) mechanism development and the seismic energy dissipation process in the RC columns marginal zones) were registered in the analytical research and the experimental studies on seismic platforms. The fragile rupture mechanism of the vertical structural elements produces the segmentation of the superstructure into rigid and fragile segment portions. In these conditions, the fundamental seismic response mechanisms and the seismic design elements of the MR RC frame structures found in current practice and considered in actual seismic design standards are specified through comparative methods. In the final chapter of the current theoretical research study, it were specified the main conclusions and immediate improvement necessity of the ductile seismic design concept for MR RC frame system.