Role of punching shear reinforcement in the seismic performance of flat slab frames

• Published in: Engineering structures Vol. 207; p. 110238
• Main Authors: Isufi, Brisid, Cismasiu, Ildi, Marreiros, Rui, Pinho Ramos, António, Lúcio, Válter
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.03.2020; Elsevier BV
• Subjects: Aseismic buildings; Building codes; Cyclic loading; Cyclic loads; Earthquakes; Flat plate; Flat slab; Fragility; Headed studs; Horizontal loads; Lateral loads; Mathematical models; Nonlinear analysis; Numerical models; Performance-based engineering; Punching; Punching shear; Reinforced concrete; Reinforcement; Seismic activity; Seismic design; Seismic loading; Seismic response; Slabs; Studs; Cyclic loading; Punching; Performance-based engineering; Seismic loading; Flat slab; Headed studs; Flat plate; Fragility
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2020.110238

•Fragility functions derived for experimentally calibrated flat slab frames.•Punching shear reinforcement improves overall performance of flat slab frames.•Damage limitation criteria remain critical even with punching shear reinforcement. Horizontal cyclic loading tests of flat slab–column specimens indicate that a considerable enhancement of the drift capacity can be achieved by introducing punching shear reinforcement. However, seismic design codes either do not recommend or do not cover buildings in which flat slabs are part of the primary lateral load resisting system. Nonetheless, flat slabs are popular, even in earthquake-prone areas. The purpose of this paper is to contribute towards a better understanding of the benefits and limitations of using punching shear reinforcement in the seismic performance of such structures. To this end, nonlinear static analyses and a set of fragility functions are derived for two reinforced concrete three story frame models. To minimize modelling uncertainties, the numerical models are calibrated based on two laboratory specimens (one without punching shear reinforcement and the other with headed studs) tested under reversed horizontal cyclic loading. The results show that the performance of the frames can be improved by introducing punching shear reinforcement. However, it is shown that the inherent flexibility of slab–column connections under lateral loading remains a limiting factor even when punching shear reinforcement is provided.