Looking for sinkholes as Bertha burrows under Viaduct

Bertha the tunneling machine will slowly grind its way below the foundations of the viaduct over the next two weeks.

Officials say they’ll be watching the ground closely. Nobody wants a sinkhole to threaten the Viaduct.

TRANSCRIPT:

Vey Damneun wasn’t looking down, so she didn’t notice the little blue and magenta paint marks on the street.

And she wasn’t looking up, so she didn’t notice the equipment mounted on top of the building near the Seattle Art Museum.

I only knew about it because I Googled it.

KUOW: "Do you see that thing up there on top of that building that looks like an old stove pipe?"

Damneun: "Yeah."

KUOW: "That is sending out laser beams to – see across the road, there’s all these blue paint marks."

The lasers measure whether the marks on the ground have sunk.

David Sowers with the state transportation department says he’s not expecting any sinkholes.

Sowers: "It’s not going to be one of those things, where suddenly, 'there’s an inch of movement, what are we gonna do?' We’re going to be monitoring this during the entire duration of that. And they will be able to respond on a millimeter’s worth of movement whether there needs to be changes to how they’re operating the machine."

Vey Damneun doesn’t think those lasers will put an end to Bertha’s problems.

Damneun: "I think there’s gonna be more drama with Bertha."

The contractor says the waterfront tunnel will open in spring of 2018.