An Olympic-sized Bridge-building Challenge March 1999
Innovative material-placing equipment helps meet luxury ski resort deadlines.
Granite Construction Company of Watsonville, Calif., is known for large-scale civil engineering projects, such as dams, airports and highways. However, one of the most challenging jobs they've undertaken is a seven-mile road and bridge project in Utah.
The Park City, Utah, area is a boom town with the 2002 Winter Olympics approaching in nearby Salt Lake City. One of the developments readying for the event is Deer Crest, an exclusive 600-acre private home community in the Wasatch Mountains - with an average sales price of $950,000 per lot. In addition to approximately 150 home sites, the development will feature a luxury resort hotel, town homes, condominiums and world-class ski runs operated by Deer Valley Resort. In fact, it's the development's ski runs that bring Granite Construction and a Putzmeister telescopic belt conveyor to Deer Crest.
By the time the project is completed, eight ski runs will criss-cross the entire development, allowing homeowners to, literally, ski out their back door. Granite's project manager, Peter Higgins, said the first challenge was to create intersections to let skiers cross the winding roads that connect the development. So today, the company is in the midst of building more than 30 bridges that let the skiers pass over or under the roadway.
"Building bridges on level ground is one thing, but constructing them on the side of a mountain is one of our more interesting challenges," said Higgins. "With the inclines we're facing, it forced us to be very creative with our process."
The job requires putting precast CON/SPAN concrete arches in place then attaching Hilfiker wire retaining walls. That's the first part. Then Granite fills the retaining walls and grooms the elevation with three-inch-minus engineered fill material.
The largest bridge they created (approximately 100 feet long by 40 feet wide by 20 feet high) required placing about 10,000 cubic yards of gravel - or about 800 truck loads of material. Fortunately, Higgins said, most of the bridges are about half that size. Starting last spring and working at a fast pace, Granite has completed more than a dozen bridges in order to open the majority of the Deer Valley ski runs for the 1998/1999 ski season.
To move this huge amount of material near each bridge site, they use 35- and 40-ton articulated trucks. Then they use an excavator to place the material in a 1-1/2 yard hopper attached to a Putzmeister Telebelt TB 105 conveyor, a telescopic belt conveyor. Once the structure is in place, the maneuverability of the Telebelt lets them finish a bridge with just a three-man crew - an excavator operator, a dozer operator and a Telebelt operator.
Higgins said this was his first time to use a Telebelt, and it's an ideal solution for this situation. They considered using stationary conveyors and a large excavator to bucket the material, "But the flexibility of the Putzmeister is a real advantage," said Higgins. "We drive the machine into position, and the conveyor places the material right where we need it. This way we avoid bringing in more equipment and men to move it twice." In fact, he estimates they're saving about 25 percent of the time it would have taken otherwise. "Placing about 90 cubic yards of material per crew hour, we're moving at a very fast pace."
The other advantage of this conveyor, he added, is its height and 105-foot reach, especially on the development's steep terrain. "We're using every inch of reach to get this job done on time." By the end of 1999, the bridges will be in place, and skiers will use all of the Deer Crest and Deer Valley Resort ski runs.