Buchanan County IBRD Bridge Project: Evaluation of a Folded Plate Girder Bridge System

Project status

In progress

Start date: 03/01/13
End date: 06/30/17


Principal investigators:

Co-principal investigators:

About the research

With the assistance of the Iowa Department of Transportation (DOT) and the Institute for Transportation (InTrans) at Iowa State University (ISU), Buchanan County, Iowa was awarded a grant to construct and evaluate an innovative short-span bridge (i.e., the Amish Sawmill Bridge). The bridge was designed and constructed using folded plate girders.

This bridge utilizes a folded plate girder superstructure supported on geo-synthetic reinforced soil (GRS) abutments. To evaluate the structural behavior of the bridge, laboratory and field testing were conducted with the goal of validating the adequacy of the folded plate girder for short-span bridge construction.

Three laboratory tests were conducted on a folded plate girder specimen similar to the ones that were used on the completed bridge to study behavior at the construction stage, flexural behavior, and shear behavior, respectively. Live load field tests were performed immediately after completion of the bridge and one year after the bridge construction to evaluate the behavior of the bridge and its components. Full-scale finite element models of the bridge were established to interpret the test results.



  • FHWA Innovative Bridge Research and Deployment (IBRD) Program
  • Iowa Department of Transportation