The New I-90 Dresbach Bridge, Minnesota and Wisconsin

SEGMENTS, SUMMER 2017, VOL.61

La Crosse, Wisconsin, opened on October 21, 2016. It exemplifies how concrete segmental solutions can create a beautiful, efficient, variable-depth, long span bridge in sensitive environmental areas and in harsh winter conditions, all while achieving a new record span length in concrete for Minnesota. The new, modern, and ecologically-conscious four-lane bridge features twin concrete segmental variable-depth box superstructures that vary in width between approximately 66' and 45'. Its four-spans consist of twin cast-in-place post-tensioned concrete segmental structures built from above with form travelers in balanced cantilever. Its 508-foot main spans are the longest concrete spans in Minnesota.

Its concrete segmental structure and custom formwork creates context sensitive, signature shapes while being economical and delivered ahead-of-schedule. It serves as a gateway to the region’s transportation system and enhances area mobility. It was designed and built to replace a now-demolished, fracture critical, structurally deficient steel bridge that had insufficient shoulder and lane widths. Its low capacity caused traffic queues. The project improves safety, capacity, and access with a long-life, low-maintenance facility.

The bridge used a high-performance 8,000-psi concrete mix, an integral wearing surface, and bi-directional pre-compression of the entire concrete superstructure, making it a perfect example of how concrete segmental bridges provide a highly durable, low-maintenance, and sustainable solution for the lowest life cycle costs.

The concrete segmental bridge design allowed means and methods that provided simple solutions to a complex site. To accelerate construction, this bridge was built in four directions at once, in balanced cantilever from two piers at a time. Casting rates of four segments per week were typical for the eastbound bridge, while the westbound bridge frequently produced six segments per week. Since it was built from above in balanced cantilever, there was no need for large ground- and water-based equipment, allowing unrestricted commercial and recreational river traffic during construction and meeting a critical need for the USACE Lock and Dam No. 7 located just upstream.

The project received AGC’s 2016 Bridge Construction Award and Post-Tensioning Institute’s Award of Excellence.

Project Details

Contractor:

Ames Construction
 

Contractor Engineering Services:

 

Constructability Review/Estimating Services:

 

Construction Engineering Inspection:

WSB and FIGG
 

Form Travelers for Cast-in-Place Segments:

 

Post-Tensioning Materials:

 

Bearings:

 

Expansion Joints:

 

Prepackaged Grout:

US SPEC