Close to a million pounds of counter weight was needed to stabilize the crane for setting the precast panels into place.
When the Utah Department of Transportation (UDOT) and prime contractor Granite Construction sat down to the design phase of the Eagle Canyon Bridge project, it realized that using a standard-size crane was not an option.
Because of the bridge’s age and vulnerable state, it could not withstand the weight that a regular crane would impose upon it. The $5.29 million project consisted of a deck replacement on the eastbound bridge, with approach slab work and measures to stiffen the existing structure.
Granite suggested subcontracting OlsenBeal, a Utah-based industrial construction and maintenance company. OlsenBeal owns one of the few Kobelco SL6000 cranes in the United States, and uses it to service most of the West and Midwest.
The Kobelco SL6000 is a 600-ton (544 t) crane with a boom that can reach up to 550 ft. (168 m). Using a crane with these capabilities meant that the crane could be stationed on either side of the bridge and perform the deck replacement without compromising the structure.
Eagle Canyon Bridge carries I-70 over Eagle Canyon, which is located between the cities of Salina and Green River in Emery County. The bridge is situated around milepost 119.5 of I-70. The eastbound lanes and westbound lanes are carried on separate structures.
According to the historic bridge listing on www.bridgehunter.com, the eastbound Eagle Canyon Bridge was built in 1965. The 491-ft. (149.7 m) bridge has a steel arch design, with its largest span stretching 375 ft. (114.3 m). The August 2007 bridge inspection listed the deck condition rating as “poor”, the substructure condition rating as “fair”, and the appraisal as “structurally deficient.”
Construction began in September 2009, at which time traffic was diverted to the westbound bridge — a newer structure that has received periodic reinforcements. On October 22, the OlsenBeal crew began assembling the SL6000 which arrived in pieces filling 52 tractor trailers.
After a week of assembly and close to a million pounds in counter weight, the crane was ready to remove the existing panels and place the new 66,000-lb. (29,937 kg) slabs onto the deck. The boom was set to 335 ft. (102.1 m) in order to do half of the bridge at a time. After the first half was complete, the crew of seven disassembled the machine, moved it to the other side of the bridge and started over.
Olsen Beal of Lindon, Utah, purchased its Kobelco SL6000 in December 2008 from Kobelco Cranes North America in Houston, Texas. OlsenBeal had a need for the $6 million machine to perform the large amount of wind turbine construction that the company is contracted for.
“In 2009, we used the crane on High Plains Wind – a project in Rock River, Wyoming, that consisted of constructing 85 General Electric 1.5 mw windmills,” said Mark Olsen, project manager of Olsen Beal. “Our current project with the Kobelco is 74 GE 1.5 mw windmills in Medicine Bow, Wyoming.”
The Eagle Canyon Bridge deck was completed in mid-February 2010. Granite Construction Company, Salt Lake City division, performed the majority of the deck replacement. Granite has been in the Utah market since 1995 after acquiring Gibbons & Reed Company. Since then, Granite has been providing quality construction services and aggregate materials throughout the Salt Lake Valley, northern Utah, Idaho, Wyoming and Colorado.
The deck called for 16,318 sq. ft. (1,516 sq m) of precast deck panels. Granite placed 252 cu. yds. (192.7 cu m) of concrete for parapets and approach slabs.
Gateway Company, also of Salt Lake City, was subcontracted for the arch painting which took place in the spring. The final step was the polymer overlay, completed at the end of May by Polycarb of Solon, Ohio.
Straight Stripe Painting Inc. of Washington performed line painting, and American Traffic Services, based in St. George, handled traffic control.
Because of the low average daily traffic in this area, travelers were not delayed by the minor speed limit reduction from 75 mph to 65 mph. Lyndon Friant, resident engineer for UDOT, reported that the project was completed by its target date.
“The only delays we incurred were due to the sub-zero temperatures at night. We’d have to wait a few hours each morning for the material to heat up,” said Friant. “But using the SL6000 made the project very efficient and we finished on time.”