A Wisconsin builder has begun preliminary work on a spectacular bridge, a concrete arch a third of a mile long over Galena Creek west of Pleasant Valley.
The $45 million bridge is one of the key pieces of the extension of the U.S.
395 freeway between Reno and the Washoe Valley.
By the time the bridge is complete, Edward Kraemer & Sons, the prime contractor based in Plain,Wis., will have poured 40,000 cubic yards of concrete.
Here's a way to think about that quantity: Those big mixer trucks you see around town typically haul nine or 10 cubic yards.
The bridge also will incorporate about 10 million pounds of reinforcing steel, says Troy Martin, an Nevada Department of Transportation bridge design engineer who developed plans for the structure.
The use of all that steel results from the use of an unusual technique called "pilot truss." Todd Montgomery, NDOT's manager of the freeway extension project, explains that the bridge first will take shape in a web of steel trusses, which are stronger and lighter than a single girder.
Concrete then will be placed around the web.
NDOT late last year sought bids on traditional bridge construction as well as the pilot truss method.
Bids on the pilot truss were about $4 million lower, and engineers think it's safer for workers because it will provide greater stability during windy winter months.
Engineers believe, too, the clean lines of the arch bridge will create a landmark south of Reno.
The sharply sloping walls of the Galena Creek canyon lends itself to a cathedral arch, and the design team wanted to create a structure that was as thin as possible so the bridge would blend into the background.
The long arch under the center of the bridge its 700-foot span is longer than two football fields will be supported entirely by arches at its ends.
"It's aesthetically pleasing," says Montgomery.
"We think the people in Pleasant Valley will like it."
Along with the appearance of the bridge, engineers worried about the potential effects on the structure of geothermal activity around Pleasant Valley.
"It didn't turn out to be a big concern," says Montgomery.
"But you want to be sure of yourself."
Along with the big bridge at Galena Creek, the $79.5 million contract handled by Edward Kraemer & Sons includes another major bridge this one crossing Brown's Creek and two smaller bridges at St.
James Parkway and Corey Canyon Way.
As work on the bridges nears completion, a second NDOT contract will be awarded to build the roadway itself.
The freeway is projected to be complete in 2008.
