Title:
Force-Displacement Characterization of Well-Confined Bridge Piers
Author(s):
Eric M. Hines, Jose I. Restrepo, and Frieder Seible
Publication:
Structural Journal
Volume:
101
Issue:
4
Appears on pages(s):
537-548
Keywords:
bridges; plastic hinge; plasticity; reinforced concrete
DOI:
10.14359/13340
Date:
7/1/2004
Abstract:
This paper outlines an approach to estimating the horizontal force-displacement response of well-confined reinforced concrete bridge piers. Particular emphasis is given to the hollow rectangular piers designed to support three new toll bridges in the San Francisco Bay Area. This approach accurately assesses a pier’s elastic displacement, its spread of plasticity and plastic displacement, and its shear displacement for most ductility levels. The shear transfer mechanism inside a pier’s plastic hinge region is central to this assessment. This mechanism appears as a fanning crack pattern and results in concentrated compression strains at the base of a pier. These concentrated strains oppose the traditional notion of curvature that assumes that plane sections remain plane. The assumption that there is a linear distribution of plastic curvatures inside the plastic hinge region, however, largely overcomes the problem of relating plastic curvatures to plastic rotations, both experimentally and analytically. At nearly all ductility levels, the mean difference between analytical assessments of the spread of plasticity and results from 12 large-scale structural tests is 16% with a 12% coefficient of variation.