Innovative structural solutions for prefab reinforced concrete hall-type buildings

Background: The anti-seismic design of prefab reinforced concrete buildings is usually carried out with a conventional ductility-based approach. This implies a remarkable plastic demand on columns, as well as damages to the connections of structural and non-structural members, for seismic events with comparable intensity to the basic design earthquake normative level. Objective: In view of this, a study was developed and aimedat extending to the field of new prefab reinforced concrete structures, the application of advanced seismic protection strategies, capable of guaranteeing undamaged response up to the maximum considered earthquake normative level. Method: A benchmark building was designed as demonstrative case study for this purpose,in the three following hypotheses: (a) according to a traditional ductility-based approach; (b) by incorporating dissipative bracings, equipped with fluid viscous dampers; (c) by placing a seismic isolation system at the base, composed of a set of double curved surface sliders. Results: The results of the verification analyses show that the targeted performance for the design solutions b) and c) is obtained with sizes of columns and plinths notably smaller than those forthe conventional design. This allows compensating the additional cost related to the incorporation of the protective devices, for the dissipative bracing system, and limiting additional costs below 25%, for the base isolation solution. At the same time, a supplemental benefit of the latter is represented by greaterprotection of contents and plants, as they are fully supported by the seismically isolated ground floor. Conclusion: The study highlights the advantages offered by the two advanced seismic protection technologies in an unusual field of application, guaranteeing an enhanced performance of structural and non-structural elements, as well as reduced member sizes, as compared to the traditional ductility-based design.