The new Wellsburg Bridge over the Ohio River – connecting Wellsburg, West Virginia and Brilliant, Ohio – was jacked into place in a single day after
The tied-arch steel structure was fabricated nearby, floated into place and jacked up into place.
Mammoet’s proposed technical solution used its Mega Jack system, mounted on a barge, to jack-up and install the 3,870-tonne structure, which spans 252 metres. It was the heaviest operation of its kind ever conducted in the USA, according to Mammoet.
The option of jacking from beneath rather than lifting from above, using strands jacks, was chosen for speed, and to minimise any interruption to river traffic. The Mega Jack solution could be completed in a maximum of two days. An alternative strand jacking method would have the bridge hanging on strand jacks for at least two weeks.
Main contractor Flatiron Construction started work on its US$131m contract for the West Virginia Department of Transportation in April 2018, and is scheduled for completion in October 2022.
Lifting subcontractor Mammoet mobilised eight Mega Jack 5200 towers and eight 500-tonne strand jacks and installed the equipment onto four prepared barges in New Orleans for testing. Flatiron Construction then floated the barges to Wellsburg where Mammoet then took over the load of the bridge on its Mega Jack system.
Mammoet jacked-up the bridge with six jacking beam layers and Flatiron floated it in. Once positioned next to the bridge piers, Mammoet jacked up the bridge again, for the bridge to be floated between the piers and over the bridge bearings and the approach girder.
Mammoet’s tool kit consisted of a total of 18 jacking beam layers to cover all possible water levels during execution. In the end, the load was jacked up a total of 15 jacking beam layers on six towers and 16 jacking beam layers on the other two towers to account for variances in the interface beams, which were provided by others.
Next, a jacking-down operation set the bridge on its bearings, freeing the barges to float away.
When windy weather was forecast, the crew decided to push on and get it all done in just one day instead of the two that were originally planned.
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