Title: Detailing of Plastic Hinges in Seismic Design of Concrete Structures

Author(s): Rajesh P. Dhakal and Richard C. Fenwick

Publication: Structural Journal

Volume: 105

Issue: 6

Appears on pages(s): 740-749

Keywords: curvature; detailing; ductility; material strain; plastic hinge.

DOI: 10.14359/20102

Date: 11/1/2008

Abstract:
In recent revisions of the structural design codes in New Zealand, a number of changes have been made to seismic design provisions. One of the more significant revisions was the way in which the level of detailing is determined for potential plastic hinges. Previously, the level of detailing was based principally on the structural ductility factor, which is broadly similar to the reduction factor R used in U.S. practice. With the revision, the level of detailing is based on the predicted magnitude of curvature that a plastic hinge is required to sustain in the ultimate limit state. This paper explains why the structural ductility factor does not give a reliable guide to the deformation sustained in an individual plastic hinge. In addition, based on test results of 37 beams, 25 columns, and 36 walls, design curvature limits are proposed for different categories of plastic hinge.