Title:
Seismic Performance of Circular Columns with
Low Longitudinal Reinforcement Ratios
Author(s):
M. J. Nigel Priestley and Gianmario Benzoni
Publication:
Structural Journal
Volume:
93
Issue:
4
Appears on pages(s):
474-485
Keywords:
bridges (structures); columns (supports); cracking
ductility; earthquake-resistant structures; shear strength.
(fracturing);
DOI:
10.14359/9706
Date:
7/1/1996
Abstract:
Two large-scale circular columns with low longitudinal reinforcement ratios were tested under cyclic inelastic lateral displacements simulating seismic response. The first column had a longitudinal steel ratio of 0.5 percent, one-half that specified as a lower limit by ACI design rules, and was intended to investigate ductile flexural response of columns with low steel ratios. The second column, with 1.0 percent steel ratio, was intended to investigate whether shear strength was influenced by steel ratio. Both columns performed well. Column I exhibited stable flexural response at displacement ductilities up to PA = 10 before failing in shear; while Column 2 failed in shear at PA = 4, somewhat higher than the expected ductility level. Response of the two columns indicates that current lower design limits for steel ratio could be reduced without detrimental influence on flexural response, and that shear strength of columns does not appear to be influenced by longitudinal steel ratio.