Projects

Project Description

Located in the Columbia River Gorge just south of the Bonneville Dam on the Oregon side of the river; this project was part of ODOT’s OTIA III bridge program and served to replace the existing bridge that supports the two eastbound lanes of I-84 over Moffett Creek. The original structure was constructed in the 1960’s and had deteriorated faster than anticipated, and was in need of replacement.

While the project site was scenic, it was also very challenging. The terrain around the bridge was steep and rugged, and had an elevation drop of 109’ from top of bridge deck to the creek below. The new bridge was constructed in almost the same alignment as the original one, with half of the new structure overlapping with half of the existing, this required the new bridge to be built in three stages to reduce traffic impacts, given the importance of I-84 to the travelling public. Also, the bridge is situated in close proximity to the Historic Columbia River Highway State Trail, which is one of the busiest trail networks in the state. These conditions created logistical and phasing challenges with even the most routine work activities that needed to be overcome with concentrated planning and strategic sequencing of the work.

The new bridge is 460 feet long, three-span steel plate girder bridge that is founded on 6-foot diameter and 8-foot diameter drilled shafts located at the abutments and interior bents, respectively. The bridge has an uncommon precast concrete façade panel system that is bolted to the exterior steel girders, giving the bridge the appearance of being constructed entirely out of concrete. The project also included the construction of nearly 15,000 SF of retaining walls, varying in type such as MSE precast, soldier piles with cast-in-place fascia, and cast-in-place gravity wall. All concrete elements feature a ‘Teton Drystack Stone’ finish that were stained a combination of dark gray and brown to match other structures in the Columbia River Gorge that blend in with the surrounding landscape.