Seattle’s Alaskan Way Viaduct has dropped 1.2 inches in the past month, spurring SR-99 tunnel contractors to stop pumping out ground water from the soil that surrounds the malfunctioning $80 million boring machine, the world’s largest of its kind.

Over the weekend, state surveyors discovered that the Viaduct is sinking in an uneven manner, meaning more delays to getting Bertha up and running and doing what she was supposed to do: dig a 1.7 mile tunnel along the waterfront. The $2 billion tunnel was to have been ready next December, but it’s now a year or more behind schedule.

The contraption, built in Japan and shipped here in the spring of 2013, has been stuck in the mud, 60 feet below ground near South Main Street, since Dec. 7, 2013. Bertha had completed only about 10 percent of her mission when she went on the blink.

Crews have been toiling for months to did a 120-foot hole so that a crane can dredge up to the surface Bertha’s broken cutter head and fix it. Seattle Tunnel Partners figured they’d have the machine repaired by March, but additional delays are now more than likely.

The full City Council was to get a briefing on this situation this afternoon.

When all the parts of the viaduct sink evenly, at the same pace, it’s not such a worrisome issue, but things can get dicey, says the Washington State Department of Transportation, if the settling is uneven.

“When you remove water from underground, there’s a tendency for the ground and the mechanics of it to consolidate. The soils could be consolidating immediately adjacent to the access pit,” says David Sowers with the WSDOT.

According to WSDOT, the viaduct is still safe for cars.

“We don’t think the viaduct is in any risk to the traveling public right now. It’s still safe. We’re not taking any measures to close the viaduct based on one inch of movement.”