The viaduct has stopped sinking.
Crews with the Washington State Department of Transportation found no additional settling in the structure during a quarterly inspection last week Tuesday.
Bents 93 and 94, the two pairs of columns and their cross braces between Columbia and Yesler streets, have not moved since measures taken in March, and since new foundations were completed in April.
"This is good news, but the viaduct is still vulnerable in an earthquake," said Ron Paananen, Washington State Department of Transportation Urban Corridors Office deputy director, in a press release Friday. "The work done to strengthen the columns was a temporary repair."
These columns have been the worst, sinking approximately 5 1/2 inches since the Nisqually earthquake in 2001.
At 6 inches, transportation engineers had said repairs would be required. Rather than wait until it was necessary, or too late, work began last October, the first of six Moving Forward projects paid for by $915 million from the state.
Crews drove steel rods and poured concrete around the four failing foundations, through loose fill another 30 feet deeper than the original pilings, into stable soil. These perimeters of pilings seem to be supporting the structure.
The new foundations, even at $5 million, are considered no more than a patch. Governor Christine Gregoire promised this part of the viaduct - from King Street to the Battery Street Tunnel - will be razed in 2012.
An advisory committee meets monthly to evaluate what the replacement will be - a tunnel, a bridge, a new viaduct, a surface boulevard, or some combination. The committee's recommendation, and the transportation department's decision, will be proposed to the state legislature in January.
The next meeting of this Alaskan Way Viaduct Stakeholders Advisory Committee will be 4 p.m. to 7:30 p.m. Thursday in the Bertha Landes Room in City Hall. The meeting is not open for general comment, but is open to the public.
Matthew G. Miller is a freelance writer who may be contacted through wseditor@robinsonnews.com.
