Title: Cyclic Lateral Loading of Nonductile Slab-Column Connections

Author(s): Ian Robertson and Gaur Johnson

Publication: Structural Journal

Volume: 103

Issue: 3

Appears on pages(s): 356-364

Keywords: loading; punching shear; slab

DOI: 10.14359/15313

Date: 5/1/2006

Abstract:
Flat slabs with discontinuous bottom reinforcement are susceptible to progressive collapse if punching shear failure occurs at a slab-column connection. Many such failures have occurred in past earthquakes, resulting in significant loss of life. The evaluation of older flat-slab buildings must include a realistic prediction of the response of the slab-column connections. Considerable research has been performed on connections with continuous slab reinforcement; however, there is a lack of data on the performance of slab-column connections with discontinuous reinforcement. The research presented in this paper involved the cyclic lateral loading of six slab-column connections with discontinuous slab reinforcement typical of flat-slab buildings built prior to 1970. Punching shear failure does not appear to occur earlier than in equivalent specimens with continuous reinforcement; however, the consequences are significantly more severe. Based on this and prior research studies, a model is proposed for estimating the lateral drift at which punching failure may occur.