Effect of abutment modeling on the seismic response of bridge structures

    Authors

    A. Aviram; K. R. Mackie;B. Stojadinovic

    Comments

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    Abstract

    Abutment behavior significantly influences the seismic response of certain bridge Structures. Specifically in the case of short bridges with relatively stiff superstructures typical of highway overpasses, embankment mobilization and inelastic behavior of the soil material under high shear deformation levels dominate the response of the bridge and its Column bents. This paper investigates the sensitivity of bridge seismic response with respect to three different abutment modeling approaches. The abutment modeling approaches are based on three increasing levels of complexity that attempt to capture the critical components and modes of abutment response without the need to generate Continuum models of the embankment, approach. and abutment foundations. Six existing reinforced concrete bridge structures, typical of Ordinary Bridges in California, are selected for the analysis. Nonlinear models of the bridges are developed in OpenSees. Three abutment model types of increasing complexity are developed for each bridge, denoted as roller, simplified, and spring abutments. The roller model contains only single-point constraints. The spring model contains discrete representations of backfill, bearing pad, shear key, and back wall behavior. The simplified model is a compromise between the efficient roller model and the comprehensive spring model. Modal, pushover, and nonlinear dynamic time history analyses are conducted for the six bridges rising the three abutment models for each bridge. Comparisons of the analysis results show major differences ill mode shapes and periods. ultimate base shear strength, as well as peak displacements of the column top obtained due to dynamic excitation. The adequacy of the three abutment models used in the study to realistically represent all major resistance mechanisms and components of the abutments, including an accurate estimation of their mass, stiffness, and nonlinear hysteretic behavior, is evaluated. Recommendations for abutment modeling are made.

    Journal Title

    Earthquake Engineering and Engineering Vibration

    Volume

    7

    Issue/Number

    4

    Publication Date

    1-1-2008

    Document Type

    Article

    First Page

    395

    Last Page

    402

    WOS Identifier

    WOS:000262725600007

    ISSN

    1671-3664

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