Half-mile section of Pacific Highway to close for road stabilization
Robin Washington, Public Works
Vancouver, WA – About a half-mile section of Northwest Pacific Highway near La Center will be closed to all traffic for about two months beginning Friday, July 6.
The closure is necessary to stabilize a 600-foot section of Pacific Highway near Jenny Creek. An underground landslide has been moving about a ½ inch per year since monitoring started in 1999. The movement has caused repeated cracking in the roadway and created areas of sunken pavement.
While the work is going on, no vehicles will be able to pass through the construction zone because 600 feet of roadway will be completely removed. Public Works has coordinated with police, fire and other emergency responders, as well as local residents.
Detour maps are available at www.clark.wa.gov/publicworks/roads/pacific.html. In addition, signs will alert drivers to the upcoming closure.
The project contractor is Nutter Corp. of Vancouver. The entire project, including design, is expected to cost about $2 million, with 80 percent of the money coming from the Washington State County Road Administration Board.
This project will use a “deep patch” technique to create a strong but flexible road that can withstand some slide movement.
In the 600-foot-long slide area, the contractor will excavate to about 6 feet below the road. Once excavation is complete, a durable geotextile fabric will be laid down, followed by a layer of rock that will be wrapped in the fabric, something like a burrito. The contractor will repeat this process and create four wraps of geotextile fabric and rock.
Finally, the contractor will build a wider road on top of the wraps and put down new asphalt over the remainder of the half-mile section. Once complete, this portion of Northwest Pacific Highway will have two 12-foot lanes, 2-foot shoulders, guardrails and facilities for collecting and treating polluted storm runoff.