The Ross Island Bridge crosses the Willamette River and is a major southwest – southeast route for the Portland metropolitan area. The east approach of the bridge crosses over Oregon Route 99E, a high-speed arterial. The bridge approach also passes over a live railroad line on the Martin Luther King Jr. and Grand Avenue Viaducts. This project was the first phase of a larger project involving replacement of the two viaduct structures that cross over Division Street and the Union Pacific Railroad right-of-way near the Oregon Museum of Science and Industry on the banks of the Willamette River.
The project included the open trench placement of 6,175 feet of new 3- to 36-inch PVC, reinforced concrete, and HDPE pipelines for potable water, storm sewer and sanitary sewer, through contaminated soils and wood waste in an older industrial area of east Portland. The contract stipulated that flows would continue during construction and JWF designed a detailed sanitary diversion flow plan to ensure no interruption in service to local residents. The project also required pipe ramming of 265 feet of 36-inch steel casing with ductile iron liner pipe for municipal water lines under active Union Pacific and Oregon Pacific Railroad lines. JWF performed cold-plane pavement removal, constructed new hot mix asphalt concrete (HMAC) and Portland composite cement (PCC) surfaces, curbs, walks, driveways and other such structures. In addition, we installed new traffic control, guidance and illumination devices. A cathodic protection system was installed to mitigate the effects of corrosion on external surfaces of the buried pipe.
This challenging project required JWF to creatively manage the re-sequencing and redesign of every manhole and pipeline on the project. We were able to continually update the project schedule and supply additional management and superintendents to successfully complete the project.
During the project construction, we encountered unidentified storage tanks and contaminated soils and groundwater on the site. To creatively manage the schedule to mitigate delays and eliminate the environmental impacts, we received Oregon Department of Environmental Quality approval and were able to treat the 10,000 cubic meters of soil with Portland cement and recycle it as trench backfill.
A portion of the 36-inch diameter sewer pipeline was located in an old lumber mill site with sawdust beneath the pie alignment that wouldn’t support the pipe. Due to design issues, ODOT planned to delete this scope of work from the project. This component of the work was critical to the completion of the project and an upcoming $60 million bridge construction project located at the same site. JWF worked with ODOT to design a trench section utilizing lighter pipe and lightweight backfill material consisting of pumice rock and Styrofoam block backfill under the heavily traveled street in an industrial section of Portland. This unique solution allowed the project to be completed on schedule and did not impact the bridge construction which began as JWF was demobilizing from the site.
