SRF partnered with Kraemer North America on a value engineering effort for the replacement of the US 52/IA 64 bridge over the Mississippi River overflow in Iowa. The project focused on optimizing both the deck and pier substructure design to improve constructibility and reduce scheduling risk for this critical river crossing.
Enhancing Constructibility and Reducing Schedule Risk
The original design called for a four-span, 376-foot by 40-foot bridge constructed using accelerated bridge construction (ABC) methods. Drilled shaft foundations were planned for the new piers, which were to be constructed outside the footprint of the existing bridge prior to demolition.
SRF’s bridge design and engineering services introduced a more efficient approach through value engineering. Key recommendations included:
- Transitioning to a conventional cast-in-place deck, simplifying construction logistics
- Lowering the elevation of the precast, post-tensioned pier cap
- Enabling pier construction and post-tensioning to occur prior to demolition of the existing structure
Mitigating Schedule Risk Through Early Pier Work
By adjusting the pier cap elevation, SRF’s solution allowed critical substructure work to take place before the limited ABC closure window. This modification gave the contractor greater flexibility in scheduling and reduced overall project risk by decoupling demolition from the start of major pier construction.
SRF’s collaboration helped Kraemer North America optimize sequencing while maintaining structural performance and safety.
Internal Category:
Bridges & Structures
More from:
Minneapolis, MN
