NEHRP Clearinghouse

Title
Cumulative Seismic Damage of Reinforced Concrete Bridge Piers.
File
PB98108707.pdf
Author(s)
Kunnath, S. K.; El-Bahy, A.; Taylor, A. W.; Stone, W. C.
Source
National Center for Earthquake Engineering Research, Buffalo, NY.; Federal Highway Administration, McLean, VA.; California State Dept. of Transportation, Sacramento. Office of Structures Design., October 1997, 142 p.
Identifying Number(s)
NISTIR-6075
Abstract
A comprehensive experimental study was undertaken in this research effort to investigate cumulative damage in reinforced circular bridge piers. Twelve identical quarter-scale bridge columns, designed and fabricated in accordance with current AASHTO specifications, were tested in two phases. Phase II testing was composed of a series of analytically predicted displacement amplitudes representing the bridge response to typical earthquakes. Test observations indicate two potential failure modes: low cycle fatigue of the the longitudinal reinforcing bars; and confinement failure due to rupture of the confining spirals. The results of the testing were also used in an analytical study of cumulative damage. It was found that none of the currently available damage models consistently predict observed damage limit states though fatigue-based models demonstrated better reliability. It was further observed that the energy-dissipation capacity of members is path-dependent, hence, models of seismic damage that rely only on measures of energy dissipation cannot predict failure if it is not related to ductility.
Keywords
; Failure modes; Bridges (Structures); Seismic design; Damage assessment; Reinforced concrete; Columns (Supports); Structural failure; Earthquake damage; Dynamic response; Earthquake engineering; Fatigue limit; Cyclic loads; Displacement; Hysteresis; Ductility; Dynamic structural analysis