Bypass has a story behind its construction
The first phase of the Newberg-Dundee bypass opened Jan. 6 and drivers can now ply the four-mile stretch of two-lane asphalt that connects Highway 99W in Dundee with Highway 219 southeast of Newberg. The bypass may not look much different than other thoroughfares in Oregon, but it required innovative designs that fulfilled both aesthetic and structural design considerations to make it a reality.
"This was one of the toughest and most challenging projects that ODOT (Oregon Department of Transportation) has been involved with during the past 50 years or so," said ODOT spokesman Lou Torres. "From an environmental, land use, political and construction perspective … there were hurdles to overcome throughout the process."
ODOT and the city of Dundee agreed on the southern-most bridge design in 2013 after several meetings and discussions. Dundee officials and the citizenry did not want the bypass to look like any other thoroughfare, but wanted the design to reflect the area.
"Citizens of Dundee were concerned about the look of the bridge," said Dundee Mayor David Russ. "There were five or six meetings at least where we discussed this."
Part of the design reflects the river, Russ said: "The blue is the river and in the blue there is a little split and that would be Ash Island. The railings above it are in multiple sizes and the color is reddish brown because we have the red hills of Dundee."
Additional discussion in Dundee revolved around what design to place on the two pillars located on either side of Highway 99W below the overpass. The symbol they agreed on is a new design of a leaf.
"We asked (ODOT) if we could put our city logo on the pillars," but the department said the city couldn't use the city's logo of a stemless wine glass, Russ said. "We created a new leaf-shaped logo to put there instead."
The aesthetic considerations were minor when compared to the structural design of the bypass,
"When comparing the 10 bridges, the curved, post-tensioned concrete box girder carrying Wynooski Street over the bypass was the most significant technical challenge," said Matthew Stucker, ODOT regional bridge lead engineer. "The soft, compressible soil underlying the whole project site was a challenge on all fronts. Settlement of the various embankments had to be considered in the bridge foundation design."
Recycling large beams from an ODOT project near Corvallis were transferred north for the bypass.
"One of the unique aspects of this project was the 'adoption' of 112 beams from another Oregon project," Stucker said. "We fit the existing beams into the design of four bridges on the project and saved the project over $1 million!"
A wetland field survey conducted by ODOT found that there were around 30 wetlands protected by the Clean Water Act in the path of the bypass. Construction on wetlands have various types of impacts that include bridge shading, partial loss of wetland area, changes in drainage patterns, exposure to stormwater runoff and changes in wildlife values.
To minimize the impact and footprint to wetlands ODOT modified and or shifted the bypass to avoid wetland areas and minimized the number of stream crossings, thus the reason for the 10 bridges.
ODOT included in the bypass design addressing potential erosive impacts and treated the flow of the water via bio-filtration ponds. You can see one filtration pond in the circle area at one of the exits/entrances of the bypass on the Dundee side. After the filtration process, the clean water will flow into the wetlands and then to streams nearby.
"Building the project on a brand new alignment and challenging geography required us to move many tons of soil and rock throughout the project," Stucker said. "This project was unique because of the architectural design aspects of the sound wall and ornamental features on the bridge over 99W south of Dundee and the long bridge in south Newberg. The long bridge incorporated unique reinforcement material (glass-fiber reinforced polymer bars) to reduce the weight of the concrete sound wall on the bridge. This material is also very durable and non-corrosive. There is 6,650 lineal feet of bridge on this project … nearly one-third of the length of the bypass itself!"