A long crack on South King Street, which may or may not have been deepened by the Highway 99 tunnel project, was filled with asphalt Friday.
“It’s just like a pothole repair,” said Rick Sheridan, spokesman for the Seattle Department of Transportation. The fix followed findings by Seattle Tunnel Partners, using ground-penetrating radar, that there are no voids beneath the roadway, and it is safe to use. Such air pockets would have posed a safety hazard, as happened in 2009 following Sound Transit’s Beacon Hill Tunnel project, where a house was nearly swallowed by one of nine voids.
The King Street crack existed in 2011, images from Google Earth show. However, the crack Thursday appeared much wider, and a new survey marker was pounded into an indentation there. Government teams and some citizens are feeling edgy because the corner of First Avenue South at South King Street is where state transportation department surveys have found 1.4 inches of soil settlement, near the Highway 99 tunnel work site. Mayor Ed Murray even held a news conference as reporters converged on the site.
Officials are investigating whether groundwater pumping near stuck tunnel machine Bertha in November has caused damage to historic Pioneer Square. There are many other potential factors, including weak soil, old utility lines, heavy trucks and tidal flows.
Building examinations and surveys continue, and the City Council is scheduled to hear an update from tunnel officials on Monday.