Bridge construction taking shape
By RICK WOOD Staff Reporter
Work continues on the Mark W. Clark Bridge replacement with the installation of eight bridge shaft foundations. Commuters caught in a backup during a single-lane closure of the Mark W. Clark Bridge on SR 532 Friday morning may have wondered how work on the replacement bridge is coming along.
Washington State Department of Transportation (WSDOT ) spokesman Dave Chesson said crews are just finishing up pre-construction work that required regular lane closures on the bridge.
"We are currently constructing eight bridge shaft foundations," said Chesson. "All eight shafts will be built by mid-October."
Construction crews will install four shafts on the west side and four on the east side.
The shafts on the east side were completed last week.
"We will begin constructing the four on the west side next week," he said.
Drivers will also notice more crane activity on both ends of the bridge, said Chesson. In November and December, after the shafts are built, crews will build the columns and improve the soils below the approach ramps with a process called "store columns," he said.
When this work is complete, crews will build the retaining walls for the approach ramps — first the east end then the west end, said Chesson.
The retaining wall work will last through the first couple months of 2010, he said. Moving forward, crews will be able to work adjacent to the bridge without closing a lane on the bridge as often, said Chesson.
Crews will continue to close one lane of the bridge as needed, he said. "In the beginning of 2010, crews will set the girders on the new bridge," said Chesson. "Drivers should expect several short-term nighttime closures of the existing bridge while crews lift and place the 190-foot centerspan girders into place over the water."
According to Chesson, the closures should not last more than 15 to 20 minutes. "Emergency vehicles will always have access to the bridge," he said.
The new bridge will be open to traffic by the end of 2010 and the old bridge will be removed after the opening of the new bridge, he said.
Replacement of the existing bridge, between Stanwood and Camano Island, began earlier this year. The new bridge, part of an $84 million safety improvement project, will provide one lane in each direction and shared 14-foot shoulders to accommodate bicyclists and pedestrians and allow room for vehicle breakdowns. The replacement will meet stricter earthquake standards and require less maintenance, said Chesson.
Dave Chesson may be contacted at 360-757-5970 or via email at chessod@ wsdot.wa.gov.
