A project to rehab a bridge over I-205 in Oregon to withstand earthquakes got a boost recently from North America’s largest hydraulic casing oscillator, nicknamed Oscar.
(To watch a video of Oscar the Oscillator in action, check out the video at the end of this story.)
The 100-ton, two-story-high oscillator, built by German company Leffer and mounted to a crane, will be used to bore 200 feet beneath the Willamette River to install shafts to support the Abernethy Bridge in Clackamas County. The shafts will be pushed and rotated into the ground until they can be anchored in bedrock to enable the bridge to withstand a major earthquake, according to the Oregon Department of Transportation.
Oscar traveled in pieces by ship through the Panama Canal, ODOT says. After it got to the Port of Tacoma, the pieces were transported by truck to the worksite where they were assembled. Oscar started work December 7 and is scheduled to complete his job in late 2024.
The bridge will also be widened from two to three lanes in each direction with an additional auxiliary lane to enter and exit I-205. The new foundations for the bridge will be built beside the old ones. The northbound and southbound bridges will be widened with lanes on the outside, built one at a time. The bridge decks will then be slid apart 8 feet each, then the bridge decks will be connected at the center to complete the widening. The old supports will be removed, according to ODOT.
The project is part of the first phase of improvements to I-205 between West “A” Street in West Linn to Main Street in Oregon City. Construction is scheduled to end in 2025.
Kiewit Infrastructure West Co. is the general contractor on the project. Subcontractor Malcolm Drilling owns the oscillator and is performing the deep-shaft installment.
