Kiewit Infrastructure West Co. has begun replacing the Virgin River Bridge No. 1 on Interstate 15 near the town of Littlefield in northwest Arizona. Kiewit is working as construction manager at risk for the $56-million Arizona Dept. of Transportation project.

“The contractor and its team will be replacing the bridge in its entirety and modifying the existing five-span structure to a three-span structure in the process, thus eliminating two columns and associated foundations in the river bottom,” says Brenden Foley, ADOT’s assistant district engineer of construction for the Northcentral District.

Kiewit’s scope includes cofferdams to construct footings on approximately drilled shafts 100 ft deep. In addition, the team will replace the abutment foundations, piers and the bridge deck and add pavement, pavement markings, guardrails and signage.

The Kiewit team also will erect a three-span temporary bridge above the river for construction access to build the bridge, explains Kiewit project manager Matt Lacey.

ADOT has divided the project into two main phases: a construction phase of 900 calendar days for demolition of the old bridge and construction of the new one, followed by a one-year landscape establishment phase to monitor and maintain the revegetation process.

Within its scope, Kiewit is completing the project in five phases.

For the most part, phase one will involve work below the bridge without impact to motorists, Foley explains. This phase will establish the staging area and access roads to the river bottom, as well as construction of the substructure, including drilled shafts, columns and piers.

During phase two, the south half of the bridge (northbound lanes) will be constructed by shifting all traffic to share the north half of the bridge (southbound lanes), with one travel lane in each direction.

In phase three, traffic will shift to the completed northbound lanes to share that portion of the bridge, with one lane in each direction, while Kiewit constructs the southbound lanes.

Traffic flow returns to normal patterns for phase four, but with one lane in each direction, while crews complete the final concrete placement of the bridge deck.

The final phase five will complete roadway paving and open up both lanes in each direction, with traffic shifted back to normal patterns on the new bridge, as well as final cleanup and revegetation.

“The proximity of the river and numerous protected species and plants requires a comprehensive environmental management program,” Lacey explains.

All construction is scheduled for completion in May 2024. Standard penalties apply if work is not completed within the allotted time frame, and no early delivery incentive is included, Foley says.

The rebuilding of Bridge No. 1 continues a series of ADOT rehabilitation projects on the seven I-15 Virgin River bridges that began in early 2014. To date, minor repairs and resurfacing of decks on Bridges No. 2, No. 3 and No. 7 have been completed and, most recently in 2016, a major reconstruction of Bridge No. 6, which included widening and replacing the superstructure.

The remote Arizona Strip roadway is a vital transportation link between Salt Lake City, Las Vegas and Los Angeles and part of the CANAMEX Corridor linking Canada and Mexico. As a result, the project will include a mobile app used during construction to keep travelers informed.

“This will allow people driving through the corridor to get information on any temporary closures, delays, traffic control configurations and other construction-related updates,” Lacey says.