Historic Route 30 wound its way along steep cliffs overlooking the south bank of the Columbia River. The Columbia River Highway Trail follows the same path.
During construction, GeoEngineers monitored micropile installation to verify that the contractors completed abided by required design standards.
To adapt the road safely for pedestrians, many of the aging structures and earthworks required additional support or replacement.
A total of 46 micropiles were needed to support the Summit Creek Viaduct Bridge.
Historic Columbia River Highway Trail
Repurposing a historic highway as a picturesque trail for public use.
The Historic Columbia River Highway was one of the country’s first purposefully built scenic routes. Samuel Hill, a leading advocate for transportation in the Pacific Northwest in the early part of the 20th Century, imagined a road bringing the era’s Model T drivers to the natural beauty of Oregon’s Columbia River Gorge. In 1922 the road become reality. U.S. Route 30 wound its way through mountains, lush slopes and waterfalls—and launched a national tradition of scenic byways.
When modern I-84 was built the Columbia River Highway fell into disuse, and sections of the road were gradually closed to traffic through the years. Now, the U.S. Department of Transportation is working with the state of Oregon to repurpose historic Route 30 as a walking and biking trail for the public. The historic road alignment included bridges, steep slopes, and tunnels. To adapt the road safely for pedestrians, many of the aging road structures required additional support or replacement.
GeoEngineers provided geotechnical recommendations for several important bridges along the Columbia River Highway Trail as a subconsultant to Inland Foundation Specialties.
Approach
- GeoEngineers’ team used geotechnical exploration data from other contractors as the basis for our recommendations for the Summit Creek Viaduct and Lindsey Cut Bridges.
- The team gave specifications for a total of 46 micropiles to support the Summit Creek Viaduct Bridge structure.
- During construction, GeoEngineers monitored micropile installation to verify that the contractors abided by required design standards.
- Finally, the team designed and implemented micropile tests to verify their load-bearing capacity and performance.
Results
GeoEngineers’ careful geotechnical analysis and design work for two bridges along the Historic Columbia River Highway Trail helped reinvent a historic highway as a dynamic trail network for public use. Samuel Hill’s dream of inviting the public into the Columbia River Gorge’s natural beauty is alive once again for a new generation of Oregonians.
