Cumulative seismic damage of circular bridge columns: Variable amplitude tests

    Authors

    A. El-Bahy; S. Kunnath; W. Stone;A. Taylor

    Comments

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    Abbreviated Journal Title

    ACI Struct. J.

    Keywords

    bridges (structures); cyclic loads; damage; ductility; Construction & Building Technology; Engineering, Civil; Materials; Science, Multidisciplinary

    Abstract

    The findings from an experimental study to investigate cumulative seismic damage in reinforced concrete circular bridge piers is presented. Twelve identical quarter-scale bridge columns, designed in accordance with current AASHTO specifications, were fabricated and tested to failure. Results from Phase I testing, which included constant amplitude tests to determine the low-cycle fatigue characteristics of the bridge column, were presented in a companion paper. This paper summarizes results of variable amplitude testing that focused on the effects of load pth on cumulative damage. The imposed displacement histories were obtained form analytical simulations of the model column subjected to a sequence of earthquakes of varying duration and magnitude. Test observations indicate that failure is generally initiated by confinement inadequacy and the rupture of the transverse spiral reinforcement. The tests also demonstrated the potential for low-cycle fatigue fracture of the main longitudinal steel when the specimen was subjected to relatively larger displacement amplitudes, typically in excess of 4 percent lateral drift. A fatigue-based damage model, derived from the constant-amplitude tests completed in Phase I testing, was applied to the observed response of the six specimens tested in this phase. Findings from the study indicate that the energy capacity of members is ductility-dependent and that fatigue-based damage models offer a reliable means of assessing seismic structural performance.

    Journal Title

    Aci Structural Journal

    Volume

    96

    Issue/Number

    5

    Publication Date

    1-1-1999

    Document Type

    Article

    Language

    English

    First Page

    711

    Last Page

    719

    WOS Identifier

    WOS:000085762300005

    ISSN

    0889-3241

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