Modeling Techniques for the Seismic Assessment of the Existing Italian RC Frame Structures

A numerical modeling approach to capture the behavior of the various elements of older reinforced concrete (RC) frames in Italy is developed. It uses available experimental data to calibrate an approach that accounts for the strength and stiffness degradation of the members. The effects of smooth reinforcing bars on the hysteretic behavior and the overall flexural deformation capacity of members are considered. The means of accounting for strength and stiffness degradation in exterior beam-column joints is also studied and calibrated to the available experimental test data. The performance of the proposed modeling approach for older RC frames in Italy is then appraised by comparing the predictions with experimental results for two different three-story frame specimens tested both statically and pseudo-dynamically. The benefits of using the new modeling techniques for the existing RC frame structures instead of more traditional approaches is also highlighted.