| For transportation agencies, the use of integral abutments in bridges to account for movements and volumetric changes is an increasingly attractive option over installation and maintenance of expansion joints. Design of the structurally complex integral abutment bridge has been largely empirical, and research into its behavioral characteristics will promote its rational use, resulting in significant immediate and long-term economic societal benefit.; Two bridges (Hickman Road Bridge and Porter Road Bridge; Dickson County, Tennessee) built of high performance concrete were selected as case studies on integral abutment bridge behavior. The two-span bridges are ideal for studying influences of bridge skew, differential end abutment details, and differential span lengths, on integral abutment bridge behavior. The superstructures were instrumented for internal strain section profiles, and rotational and translational deformation. These systems were continuously monitored from start of construction, through five years of service. Extensive laboratory testing was performed on specimens of high performance concrete batches comprising the structural elements. Live load testing was carried out using simulated design loads, for assessment of the nature of load distribution in the select bridges. In addition to classical analytical studies, an in-depth program of nonlinear finite element analysis was performed to capture the true nonlinear behavior of the structures under design thermal, time-dependent, and live loading.; The nature of integral bridge behavior is presented from the information collected from the actual specimen bridges, which serves to verify results of in-depth analysis. Comprehensive analytical results are presented for appreciation of the effects of skew, and the details used, especially those introducing asymmetry in the structure. Finally, simplified modeling techniques are validated for efficient parametric assessment of integral abutment bridge behavior. |
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