Iowa Department of Transportation
Behrouz Shafeishafei@iastate.edu email >
Structural Engineer, BEC
About the research
The use of precast elements and prefabricated bridge segments along with accelerated construction techniques, known as accelerated bridge construction (ABC), has allowed for increased efficiency of construction, reduced safety concerns, and converted month-, or even year-, long closures into a matter of weeks, or at times, days. This tactic is growing in popularity within the bridge community, and research projects have been initiated to investigate how the construction of bridge elements can be expedited.
One such element being investigated is the integral abutment. This structural connection for bridges was introduced to eliminate the need for expansion joints between the substructure and superstructure, where the presence of water and other deteriorating chemicals caused long-term and frequent maintenance issues. Due to this area needing to be heavily reinforced, congestion issues arise when attempting to apply ABC methods. In addition to the reinforcing congestion, the construction tolerances and weight of the integral abutments cause some problems for ABC projects.
These issues are the basis for this project, which was intended to investigate the use of mechanical couplers to splice the foundation elements to the superstructure elements of bridges while applying ABC techniques. Since this was a Phase II project, the methodologies and laboratory setup for evaluating the ABC connection details were the same as that of Phase I. From the results of Phase I, three connection details were developed for investigation in Phase II. Of which, two were a revised design of the two mechanical coupler connection details tested in Phase I, and the third was a new connection detail designed through the Iowa Department of Transportation (DOT) to be used on an upcoming bridge project.
With this project completed, further investigations about integral abutment connection details for ABC applications should be conducted to provide more literature on the subject. Such investigations would be further revisions to the designs of the connection details and field monitoring of real-world applications of the connections.