The mainspan of the Hastings Bridge now boasts the longest free-standing tied-arch bridge in North America.
- Comprised of arches, girders, beams, stringers and roadway
- Length: 545 feet
- Width: 104 feet
- Comprised of steel arches and hanger assemblies
- Height of arch rib (at maximum): 94 feet
- Height of arches: varies from 6 feet to 8 feet 5 inches
- Width of arches: varies from 8 feet 4 inches to 9 feet 4 inches at the top; 6 feet wide at the bottom.
- Poured-in-place concrete deck
- 90 feet wide (barrier to barrier)
- 4 lanes of traffic + 12 feet mixed use pedestrian and bike path
The arches play an important role in supporting the Main Span, but are not the only means of support. The wider at-the-top trapezoidal shape of the arches gives an elegant and sculptural form and allows for efficient illumination of the arch. They are held in place by post-tensioned concrete knuckles and tie girders.
Arches are a terra-cotta color, with tan superstructure and piers. Hanger assemblies – like the light poles and railings – are silver.
The Main Span was built at the project’s Flint Hills Preserve staging area, near Lock and Dam #2. The arches and floor beams were built offsite and then delivered onsite as they were completed.
Crews completed the deck system (floor beams and stringers) first. Then, the arch ribs were built section by section (working from the middle out). A temporary tie girder was also constructed and formwork was put into place for the permanent tie girder.
In September 2012, the Main Span was lifted from its shoring towers and moved down to the river by self-propelled modular transports and placed on a flotilla of barges. The Main Span then was floated down the river and moved into its pre-lift location using a skid system. Finally, it was connected to hydraulic strand jacks that lifted the Main Span vertically approximately 50 feet, and crews secured the span between Piers 5 and 6.
Next, crews completed constructing the concrete knuckles and tie girders, as well as post-tensioning the Main Span.
The deck for the roadway was poured in April 2013. The process required about 2,100 cubic yards of concrete. The deck pour was a more than 12 hour process and required about 75 laborers, carpenters, finishers and operators to complete the job. While the deck “cured,” crews worked on switching over utilities, installing expansion joints and forming traffic barriers.
Finishing touches on the Main Span included applying a special surfacing coat and a low slump overlay, as well as curbing, laying asphalt and painting the hanger cables. Two lanes of traffic, one in each direction, were rerouted onto the new Hastings Bridge in early June 2013.
After crews finished constructing the northbound approach roadway and lanes all four lanes opened to traffic.