Record-Breaking Bridge Stars In Rugged Nevada Route
The critics have called it "the bridge to nowhere." It has gone through over a decade of delays and setbacks. But the 1,722-ft-long, 295-ft-tall Galena Creek Bridge, one of the costliest, most controversial projects in Nevada's history, is finally nearing completion.
Crossing a small creek in a rocky, rural patch of northern Nevada about 20 miles southwest of Reno, it will be both the country's longest cathedral-arch bridge and the linchpin of a $600-million Interstate 580 extension between Reno and Carson City.
The 8.5-mile-long, six-lane freeway bypasses a busy, accident-prone stretch of U.S. Highway 395—which runs through Pleasant Valley, a small, unincorporated community in Washoe County—that handles 40,000 vehicles daily. Northern Nevada's most congested rural roadway, the two-lane undivided highway is susceptible to high winds and head-on collisions.
Nevada Dept. of Transportation (NDOT) officials hope the extension will divert up to 70% of the traffic away from Pleasant Valley while improving safety, reducing travel time and bolstering NDOT's reputation.
"This is a signature project, a showcase of our abilities, and proof that we can handle a job of this size and complexity," says NDOT district engineer Thor A. Dyson. "Completion of this project is important for the department's psyche."
Locals, however, are sensitive about the freeway's alignment and look. The project received vociferous feedback from residents and businesses who were determined to maintain the area's scenic beauty. The freeway, as a result, hugs the 5,000-ft-tall southern mountain range. The project includes $10 million for environmentally friendly landscaping and replanting.
"We listened to the community, and they wanted to minimize [the bridge's] appearance," says Dyson. The unobtrusive appearance, however, entails heavy engineering that includes nine bridges and 5 million cu yd of tricky excavation.
The high elevation also prompted NDOT to add a $2-million Boschung deicing system with sensors and deck-embedded nozzles that spray potassium acetate in four second intervals when the temperature falls below freezing (ENR 1/15/07 p. 24). The system—a first for the state—is being installed on four bridges.
Designed by CH2M Hill Inc., Englewood, Colo., with NDOT, the project includes three miles of asphalt frontage roads, 26,246 linear ft of mechanically stabilized earth walls, 14 miles of drainage pipe and 25 miles of concrete barrier rail. It travels through rugged terrain that required 18 months of continuous drill-and-shoot blasting. Large dozers, articulating trucks and backhoes with hammer attachments broke up rock, most of which was re-used. There were 40 pieces of earthmoving machinery at work at any one time. The biggest roadway cut, nicknamed "the Matterhorn," required the removal of one million cu yd of material.
"[The cut] is located in the middle of the freeway alignment, which made hauling tough," says NDOT resident engineer Brad F. Durski. Fill removal took the equivalent of 100,000 truckloads, he says.