The new ferris wheel located on the end of Pier 57 was a longtime dream of Hal Griffith, restaurateur and owner of the pier on downtown Seattle’s Elliott Bay. GeoEngineers was brought in on the design-build team by Manson Construction for this fast-paced project. The result of the team’s effort was a sturdy foundation for the Seattle Great Wheel, a new Seattle landmark that opened in time for the summer 2012 tourist season.
“This was a fun one,” Geotechnical Engineer Lyle Stone, PE, explained. “The owner had been using another geotechnical engineer for other improvements to their pier, but the scope and schedule that they proposed for the Ferris wheel just didn’t meet the owner’s needs. Manson called us and we were able to come up with a plan that used existing subsurface explorations in combination with a pretty comprehensive test-pile program. This allowed the contractor to start installing pile as soon as the work window opened.”
During the design stage, Stone worked closely with the contractor, structural designer and owner to create piling designs and provided installation recommendations for the foundation for the wheel. Then, during the construction phase, Stone calculated pile capacities as the piles were being installed and finalized design recommendations as the foundation was being built. “It’s a lot of fun and very rewarding to engineer stuff in the field or during construction, but you need to work with an owner and a contractor who understand the risks and are willing to be flexible. We’re fortunate to have those good relationships.”
Today, the Seattle Great Wheel extends nearly 40 feet beyond the pier’s end over Elliott Bay. It can hold more than 300 passengers at a time in its 42 enclosed gondolas. And at 175 feet tall, the Seattle Great Wheel is the largest observation wheel on the West Coast.
Thanks to John Wells for permission to use the photo from his blog, Skypencil.com.
