Nebraska Local Technical Assistance Program
Nebraska Department of Transportation: Research Reports
Date of this Version
12-2022
Document Type
Article
Abstract
The research objective of this project is to study the behavior of the curved full integral abutment bridge designed in Nebraska through field monitoring and numerical simulation to 1) understand and model the complex short-term and long-term behavior of curved integral abutment bridges, 2) evaluate if the details provided in Nebraska (pile embedment over 4 ft into the abutment) can be expanded for wider design and construction practices (longer spans and larger curvature for curved bridges), and 3) better maintain existing full curved integral bridges in Nebraska based on the findings of this study (revise and optimize design, if needed). The research team carefully instrumented a curved full-integral abutment bridge following the construction schedules of the bridge starting from Jan. 2020 to Aug. 2021, and measured the abutment backfill pressure, abutment tilts, and pile movement profiles. This study documents the measurements completed between April 2021 to July 2022, including a full annual cycle since the bridge has been fully integral. A three-dimensional finite element model was developed for numerical simulation, and the backfill pressure, tilt, and pile top displacement calculated through the model and measured at the field were compared. The results demonstrate that the backfill pressure and the pile top displacement are within 5% difference, and comparable while the tilt has 20% difference between the model and field measurements. However, the change in tilt due to the annual temperature change (ambient) and the shape of the change (trend) is similar between the simulation and monitoring results. A parametric study was conducted additional to these annual cyclic measurements to study the limits of the curved full integral abutment bridge and recommendations are provided based on the findings. Continuous measurements of the backfill pressure, tilt, and pile movement is recommended until the entire bridge movements level out in several years.