The first rule of digging holes, as most schoolchildren know, is that when things are going badly, stop digging.
Through no wisdom or planning of its own, the state, in its effort to replace the Alaskan Way Viaduct, stopped digging its downtown State Route 99 tunnel one year ago. “Bertha,” the humongous machine charged with digging SR 99’s new home, broke down when a bearing filled with grit. It overheated, leaving its cutter incapable of moving dirt. On Dec. 6, Bertha celebrated its first anniversary of sitting idle somewhere under Pioneer Square.
However, Seattle Tunnel Partners (stp), the contractor managing the hole-digging, has not been idle itself. It’s been digging a second hole, a 120-foot
vertical shaft just ahead of where Bertha is stranded. The idea has been to have Bertha punch through a concrete wall into the shaft, and then engineers can extract Bertha and try to fix the design flaws. Then — maybe — stp can start digging the tunnel again.
Except that now maybe stp should stop digging the second hole, too.
On Dec. 5, the state announced that soil underneath the viaduct had sunk 1.2 inches. That can happen when you’ve got a massive hole filling with groundwater from soil saturated during this fall’s heavy rains. A few days later, the state Department of Transportation also announced that soil under Pioneer Square had sunk an inch and that some 30 buildings in Pioneer Square would need to be inspected for cracks and other possible damage.
Before it stopped digging last week, stp had excavated 84 of the 120 feet of Bertha’s rescue shaft. Workers are still pumping about 600 gallons of groundwater a minute out of the water table, so that the full 120 feet can be dug. Removing all that groundwater seems like an invitation for soil to settle further, but nobody seems to be talking about that.
Nobody, in fact, is talking much about what a fiasco the whole project has become. Some $1 billion of the original $1.44 billion stp was to be paid for digging the tunnel has already been paid out, and engineers are still struggling with how to fix a machine that may or may not be able to do the job. The state still insists that the new SR 99 will be open for traffic in less than two years (already delayed from the original 2015 completion date).
All things considered, that seems preposterously optimistic.
Meanwhile, remember those cost overruns former Mayor Mike McGinn was pilloried for worrying about? State Senate Republicans just elected their new Senate Majority Leader, Mark Schoesler, R-Ritzville. Schoesler’s known mostly for his appetite for farm subsidies, but he’s also been outspoken in his insistence on making Seattle pay for downtown tunnel cost overruns. That’s been one of the sticking points in the senate’s two-year failure to pass a transportation budget. With Schoesler now a major player in that process, suddenly the prospect of Seattle taxpayers getting stuck with insane cost overruns seems all too plausible. And all of these problems — the unproven tunnel technology, the groundwater dangers, the prospect of severe cost overruns and delays — were foreseen by tunnel critics well before the project’s approval.
It’s now been nearly 14 years since the earthquake that damaged the Alaskan Way Viaduct. The soil underneath the viaduct is settling; the viaduct now leans ever-so-slightly toward Elliott Bay. With or without another earthquake, the viaduct won’t collapse — it’ll tip over first. When and if inspectors decide the viaduct is unsafe, the state had better have a plan for all that traffic. Maybe we’ll wind up with an at-grade replacement for the viaduct after all. It’ll just cost several billion dollars more than anyone expected.