Robustness of reinforced concrete frames in seismic zone: preliminary results

This study regards a computational analysis on reinforced concrete buildings designed in a highly seismic area, with the goal to evaluate their structural robustness when a base-central column is lost, as a consequence of accidental events. In particular, two 2D frames with five floors and four spans are designed according to European and Italian standards. The two frames have the same ge-ometrical and material characteristics but different beam heights. The initial structures are then modified adopting a continuous lon-gitudinal reinforcement along the beam length. Capacity curves are obtained using the finite element software Atena 2D, by simulat-ing displacement-controlled pushdown analyses. These analyses consist of imposing a static increasing vertical displacement in the top of the central base column, and evaluate the reaction in the same point. The resulting force-displacement curves are then ana-lysed with the goal to study the capability of the structures to withstand the base column accidental removal.