I-5 Willamette River Bridge Replacement - Whilamut Passage
CM/GC [Construction Manager/General Contractor delivery method]
Hamilton was the CM/GC on this high-profile project – the first CM/GC project in ODOT’s history – and the largest and most successful bridge replacement in ODOT’s $1.3 billion OTIA III State Bridge Delivery Program, funded by the Oregon Transportation Investment Act. By replacing the bridge, ODOT improved a crucial component of the transportation corridor that connects Oregon commuters, tourists and freight haulers all along the West Coast, from Mexico to Canada.
The new bridge includes twin structures approximately 1,800 feet long, 67 feet wide and 75 feet high and feature a combination of deck arch and cast-in-place box girder spans. Upon completion, these bridges have the longest concrete arch spans in the state of Oregon. The bridges span the Willamette River, a Union Pacific Railroad mainline, four-lane highway, an extensive multimodal recreational trail system, and a new multimodal bike and pedestrian bridge. Hamilton constructed a new multimodal bridge along the highly traveled riverbank to create, for the first time, a multimodal connectivity between the cities of Eugene and Springfield.
Leveraging the full benefit of CM/GC delivery, ODOT, Hamilton, and the engineering consultant formed a fully integrated, collaborative team that proved both flexible and cost-effective. When a community vote yielded seven alternative design concepts for the main bridges over the Willamette River, this team worked to quickly evaluate each of the concepts for cost, schedule, and feasibility.
Hamilton engaged stakeholders early on and throughout the project, building trust and maintaining an open, transparent outreach and support program. Community stakeholder interactions provided the background for thorough alternatives analysis, incorporated key stakeholder and community input, and resulted in a project that met ODOT’s key transportation goals with a high level of community support.
Hamilton developed a widespread outreach program focusing on DBE firms throughout the Willamette Valley and beyond, resulting in participation well exceeding the project's aspirational goal and awarding over $17 million in DBE subcontracts.
The bridge was dedicated as the Whilamut Passage, in honor of the region’s native Calapuya tribe. “This area is where my ancestors lived, we believe, since the world began,” said a Kalapuya elder. “Our people were overjoyed.”
Innovative construction practices such as the use of Hamilton’s Bubble-Curtains to protect fish during pile driving; use of equipment fueled by vegetable-based rather than petroleum-based products, fully contained work bridges to minimize construction impact to the environment, and the use of fish by-pass systems will assure that the Whilamut Passage is memorialized as one of the most environmentally forward bridge construction projects in the nation.
Major Project Elements
This project won numerous awards including: