Topic: A different giant hog

[Slack]

Wow, Big Bertha has been stuck underground for a year!?  Stuck on a rock?  It grinds rocks!  city blocks settling around it?? I don't know about you, but this kind of human disaster holds a certain fascination for me.  The folly of man confirmed or something.

http://www.kirotv.com/news/news/ground-sinking-unevenly-downtown-seattle/njNWj/

[Johnm]

Ugh, there was an idea that was a real non-starter:  digging a massive tunnel below fill in a seismically active area in close proximity to a deep water bay.  Not Seattle's proudest moment of civic planning, John D.
All best,
Johnm

[Slack]

I remember reading something about it some time ago Johnm --- but had no idea it had turned out to be such a potential disaster.  I understand they've starting billing it as the 'worlds largest time capsule'. 

[Stuart]

Here's some more:

http://www.king5.com/story/news/local/seattle/2014/12/13/downtown-businesses-sinking-water-damage/20376591/

http://seattletimes.com/html/localnews/2025241220_berthacitycouncilxml.html

Yeah, like Johnm and other local denizens, we've been following this one for a while. Supposedly,  the original problem was caused by the cutter head running into a pipe that was used for test borings and core samples, and should have been removed prior to the start of tunneling. And the sinking of Pioneer Square is supposedly due to pumping out ground water that has to be removed so that the hole can be dug to fix problem number one. There was an engineer interviewed on the news last week who posed the question re: What happens when there's a problem once Bertha is under buildings and where there isn't easy access in the form of a straight shot down to the machine to repair the problem?

Brings to mind the "Man vs. Machine" CD of the "People Take Warning!" set. I guess it's only a matter of time before "Bertha's Blues" hits the airwaves here in the Puget Sound region.

[One-Eyed Ross]

There's a reason, even when I worked in Seattle, that I didn't spend much time down town.  After all, a lot of the area down there is fill dirt - and liquefaction is a real threat.  After all, this is the Cascadia Subduction Zone....

[Rivers]

Liquefaction is a given in that situation, I would think. I have enough trouble up here in the NYS hills running a plate compactor a few measly feet below grade if I haven't prepared the substrate thoroughly. The water comes up, mud pools form, the compactor heads straight downhill into them, and that's all she wrote.

To say the least the Seattle project looks like blinkered wishful thinking but it's easy to be wise after the event.

At the same time I find it perversely refreshing that so many people who should have known better are capable of making such a monstrous collective blunder. It makes my recent excursion, burying a rental compactor because we didn't take enough time and lay enough material on top of the mud, look like small potatoes. They're probably lucky Bertha just conked-out before it had a chance to go nose down and head for the center of the earth. Actually that might have been cheaper, now they have to try and get it out!

[Stuart]

Today's update:

http://seattletimes.com/html/localnews/2025292592_99tunnel2017xml.html

The daily struggle continues...

[Rivers]

All credit to the engineers if they do manage to overcome the problems and complete the project. I'll be following the story with great interest.

[lindy]

All credit to the engineers if they do manage to overcome the problems and complete the project. I'll be following the story with great interest.

Mark, the miracle will be if people use the tunnel when it's done. It won't have any exits to downtown Seattle, and people will have to pay $4-$6 a pop. Most people will stay with I-5, which has several downtown exits and is free. Should be a mess.

Oink--the sound of legislative pork.