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Publication Citation: Cumulative Seismic Damage of Circular Bridge Columns: Benchmark and Low-Cycle Fatigue Tests

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Author(s): A El-Bahy; S K. Kunnath; William C. Stone; A W. Taylor;
Title: Cumulative Seismic Damage of Circular Bridge Columns: Benchmark and Low-Cycle Fatigue Tests
Published: July 01, 1999
Abstract: An experimental study was undertaken to investigate cumulative damage in reinforced concrete circular bridge piers subjected to a series of earthquake excitations. Twelve identical quarter-scale bridge columns, designed in accordance with current AASHTO specifications, were fabricated and tested to failure. This paper summarizes the results of Phase 1 testing that consisted of benchmark tests to establish the monotonic force-deformation envelope and the energy capacity under standard cyclic loads, and constant amplitude tests to determine the low-cycle fatigue characteristics of typical flexural bridge columns. A companion paper will present the results of variable amplitude testing that focused on the effects of load path on cumulative damage. Test observations indicate two potential failure modes: low cycle fatigue of the longitudinal reinforcing bars; and confinement failure due to rupture of the confining spirals. The former failure mode is associated with relatively large displacements amplitudes in excess of 4 percent lateral drift, while the latter is associated with a larger number of smaller amplitude cycles. A fatigue life expression is developed that can be used in damage-based seismic design of circular, flexural bridge columns.
Citation: Aci Structural Journal
Volume: 96
Issue: No. 4
Keywords: bridges (structures); damage; reinforced concretes; piers; earthquakes; fatigue (materials); structures; cyclic loads; ductility; material properties
Research Areas: Building and Fire Research
PDF version: PDF Document Click here to retrieve PDF version of paper (1MB)