Title: Effects of Displacement History on Failure of Lightly Confined Bridge Columns

Author(s): R.T. Ranf, M.O. Eberhard, and J.F. Stanton

Publication: Symposium Paper

Volume: 236

Issue:

Appears on pages(s): 23-42

Keywords: bridges; columns; cycling; failure; reinforced concrete; shear

DOI: 10.14359/18206

Date: 5/1/2006

Abstract:
Six nominally identical reinforced concrete columns were subjected to a variety of lateral displacement histories to evaluate the effects of cycling on their failure displacement and failure mechanism. The columns, typical of bridges constructed before the mid-1970s, had circular cross-sections, low axial loads, and little transverse reinforcement. Shear failure caused five of the six columns to lose their axial load carrying ability at drift ratios between 3% and 5%. The sixth column failed in an axial-flexure mode at a drift ratio of 6%. Increasing the number of cycles at each displacement level from one to fifteen decreased the maximum displacement preceding flexure-shear failure by approximately 35%. The effect of cycling on damage accumulation was modeled with the Park-Ang damage model, a Modified Park-Ang damage model, and a Cumulative Plastic Deformation damage model. The Cumulative Plastic Deformation model correlated best with the observed damage, and it was the easiest to implement.