Virgin River Bridge
The 392-foot mammoth Hurricane Arch Bridge, which spans across the Virgin River near Hurricane, is the first steel arch bridge to be constructed in Utah since 1985.
The new structure includes the complete renovation of the existing steel arch bridge that was originally constructed back in 1937. The existing structure provided the only access across the Virgin River between the towns of LaVerkin and Hurricane, necessitating continued traffic and utilities across the existing structure while the new bridge was constructed.
The construction of arch bridges of large canyons is as challenging as bridge construction gets. The sides of the canyon walls were first pre-split and blasted in order to excavate a place for the footings. Once the anchor bolts were installed and the footings poured, Wadsworth Brothers then had to provide access for the huge cranes required to erect the bridge.
In order to support the arch until assembly was completed, tie-back towers were installed behind the abutments, and these towers were guyed to rock anchors drilled into the sandstone behind them. The bridge was then erected from each side and supported from the towers with large steel cables.
The towers were hinged at the base to allow longitudinal rotation with temperature fluctuations. The pennant cable that supported the arch segments from the tie-back towers were attached with load cells and reverse frame jacks which could monitor and adjust the individual loads to with 500 pounds.
Once the steel bridge was erected, the challenge then was forming and puring a concrete deck 120 feet in the air above the river. Every aspect of this project was difficult and dangerous and required equipment and techniques seldom used in ordinary bridge construction.
In the final stages, the renovation of the existing structure required Wadsworth Brothers to remove the original lead point paint and reinforce existing columns and cross braces by welding additional structural steel members in place. Wadsworth Brothers determined that this work could be done more effectively by disassembling the existing steel bridge down to the arches, flying each piece up to a temporary shop on the canyon bank, and performing this work on the ground rather than in the air.
Wadsworth Brothers and its team members were able to overcome each of the challenges and successfully complete one of the most difficult and aesthetically renowned bridges in the state without any injuries, accidents, or lost time. The project received the “Engineering Challenge Award” at the 2004 UDOT Engineer’s Conference, as well as “Best Heavy Project” and “Best Steel Project” in the “Best of 2005” awards from Intermountain Contractor.