Cumulative Seismic Damage of Circular Bridge Columns: Benchmark and Low-Cycle Fatigue Tests
A El-Bahy, S K. Kunnath, William C. Stone, A W. Taylor
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.
, Kunnath, S.
, Stone, W.
and Taylor, A.
Cumulative Seismic Damage of Circular Bridge Columns: Benchmark and Low-Cycle Fatigue Tests, Aci Structural Journal, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=909399
(Accessed February 28, 2024)