NCEER-97-0006 | 9/2/1997 | 192 pages |$30
TOC: The table of contents is provided.
Keywords: Experimental tests. Damage indices. Energy dissipation. Ductility. Load paths. Analytical studies. Cumulative damage models. Reinforced concrete piers. Highway bridges. Bridge piers. Low cycle fatigue. Cyclic loads. Failure modes. Longtitudinal reinforcement. Confinement reinforcement. Circular piers. Flexural piers.
Abstract: This report describes a comprehensive experimental study to investigate cumulative damage in reinforced concrete circular bridge piers subjected to a series of earthquake excitations. Twelve identical quarter-scale bridge columns, designed and fabricated in accordance with current AASHTO specifications, were involved. Testing was in two phases. Phase I established benchmark tests of the monotonic force-deformation envelope, the energy capacity under standard cyclic loads, and constant amplitude tests to determine the low-cycle fatigue characteristics of the bridge column. Phase II testing consisted 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 longitudinal reinforcing bars; and confinement failure due to rupture of the confining spirals. An analytical study of cumulative damage was also conducted. A simple fatigue-based model was used to predict cumulative damage in flexural bridge piers. Findings from this study will provide additional input into the development of performance-based design specifications. (Adapted from authors' abstract).