Title: Seismic Testing of Support Connections in Deep Hollow- Core Floor Units
Author(s): Samuel R. Corney, Jason M. Ingham, and Richard S. Henry
Publication: Structural Journal
Appears on pages(s): 735-748
Keywords: design standards; floor diaphragm; precast concrete; seismic testing
Past research has indicated that the support connections of hollowcore precast concrete floor units are susceptible to undesirable failure modes when subjected to earthquake-induced deformations. Furthermore, the vulnerabilities of the support connections may be exacerbated where deep hollow-core units are used, which have been more recently introduced into the market. The New Zealand Concrete Structures Standard (NZS 3101:2006) provides prescriptive recommendations for compliant support connection detailing for hollow-core precast concrete floors that were developed and verified for shallower depth units. An experimental program was initiated to investigate the seismic performance of the recommended support detailing with 400 mm (15.7 in.) deep units (400HC). During all five tests, the support connections performed adequately and prevented undesirable damage to the precast unit. Structures incorporating 400HC floor units are typically designed for low levels of ductility and, as such, the test results have confirmed that the detailing recommended in NZS 3101:2006 for HC units is sufficiently robust to accommodate damage well in excess of that which would be anticipated during a design-level earthquake.