Featured State
Iowa Department of Transportation
Technical Session
Monday, June 8; 2:00 – 5:00 PM
Session Chair: James Nelson, PE, Iowa DOT, Ames IA
Iowa DOT has a long history of leading innovations in bridge engineering and is one of the early lead adaptors of innovations such as Ultra High Performance Concrete (UHPC), Accelerated Bridge Construction (ABC), Structural Health Monitoring (SHM), Building Information Modeling (BIM), and various bridge preservation practices. In this session, presenters will share Iowa’s experience in using these innovations.
I-74 Corridor Reconstruction: A State-of-the-Art Design
Andrew J. Keaschall, P.E., S.E., Alfred Benesch & Company, Chicago, IL
The I-74 project in Iowa/Illinois is a $1.2 billion endeavor that involves reconstruction and widening of 8 miles of interstate which includes 3,300 feet across the Mississippi River. The signature elements of the project are basket-handle true arch bridges over the navigation channel, each with span length of 780’. The arch structures are complex with many unique features in both the superstructure and substructure.  The eastbound bridge accommodates a multi-use path outside the plane of hanger cables.
I-74 over Mississippi River: Design and Construction of the Arch Superstructures
P. Ritchie, A. Adams, T. Murphy, MODJESKI and MASTERS, Inc., Mechanicsburg, PA
The twin arch bridges carrying I-74 over the Mississippi River in the Quad Cities are currently under construction. This presentation will present an overview of the design features of these structures, and key innovations intended to achieve long service life. The construction process currently underway will be presented, with emphasis on key construction activities and current status.
More Than ABC: Expedited Bridge Design and Construction through Planning and Collaboration
Tony Bower, P.E., Stanley Consultants, Des Moines, IA
Severe floods in recent years led Iowa DOT to investigate options to reduce the impact of future events. One identified resiliency improvement involved reconstructing a portion of the Missouri river levee system alignment in Fremont County. The crossing on IA 2 was identified as an opportunity to increase conveyance of the Missouri River by replacing a constriction in the levee system with dual overflow bridges. To accomplish the expedited schedule, creative workflows were essential including the utilization of BIM models.
I-80/380 BIM PILOT PROJECT
Julie Rivera, PE, SE, HDR, Rosemont, IL
As part of the Iowa DOT’s 3D initiative for bridges, a pilot project was developed to investigate the use of Building Information Models (BIM) during design and understand the current state of the software. The project consisted of three new curved steel plate girder bridges in the I-80/I-380 Systems Interchange. Three robust models were developed, one of which was used as the signed and sealed bid document for the Design/Bid/Build project.
Use of UHPC as a Deck Overlay for improving Performance of Bridges
Sri Sritharan, Iowa State University, Ames, IA
After being in service for few years, bridges begin to show distress resulting from deterioration. Often bridge deterioration begins with cracking in the deck, followed by water and chloride infiltration into the concrete core and additional damage resulting from freeze-thaw cycles. Given the superior performance, Ultra-High Performance Concrete (UHPC) has been investigated as a deck overlay to improve the long-term performance of bridges. UHPC deck overlays have been successfully completed in Iowa projects.
Preservation and Maintenance Techniques for New and Late-Life Bridge Decks
Mohamed K. ElBatanouny, Ph.D., S.E., P.E., Wiss, Janney, Elstner Associates, Inc., Northbrook, IL
Bridge deck preservation and maintenance is of paramount importance to transportation agencies as bridge decks significantly impact the overall condition rating of the bridge, quality of service, and public’s perception of the bridge condition. As such, the Iowa DOT has funded multiple studies that focus on optimizing the type and application time of preservation actions for new and in-service decks, including late-life decks planned for future replacement. This presentation provides an overview of the studies.