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Geo floor bump!

Visited a geo site today. Bore holes (4) were installed. Roughly 20' from nearest one to front of home. Basement is 30' wide. Towards the far side of the basement, the concrete floor heaved up, breaking the slab & creating a 2" offset. Center support pole supposedly rose up to lift the steel beam & cracked the first floor drywall. No one was inside the home to verify it happened during drilling. HO (they contracted directly with the driller) & driller are locked in a dispute & the geo installer ran away from the job.



Aside from the oddities created by the ongoing disputes, which do not involve my firm, have any of you seen this type of damage caused when drilling bore-holes?

Comments

  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    Got Bentonite???

    Bentonite is an expansive clay soil, that when wetted, will expand significantly enough to do that kind of damage, and more, to a structure.



    It is VERY prevalent here in Colorado along the front range. We have "floating walls" and expansion joints on vertical plumbing stacks, and the required use of flex gas/water connectors to compensate for these destructive soils.



    I have seen it lift slabs 6" before.



    It is used in the construction of sky scrapers. They pour it into the caison holes after the concrete has set to lock the foundations into the bedrock.



    I believe it is also one of the constituents used in the conductive grout used to lock GSHP earth loop tubes into the bore holes...



    HMMMmmmmm...



    ME

    There was an error rendering this rich post.

  • meplumber
    meplumber Member Posts: 678
    Not on geo

    But I once saw a well driller hit a water vein so strong that it looked like a gyser coming out of the hole.  The vibration, just before it broke was enormous.  I would say that was the most violent geological event that I have ever witnessed on a jobsite and it did no damage to the structure, perhaps 30' away.  Other than thoroughly drench the exterior.



    Good Luck.

    Let us know the outcome.
  • Ironman
    Ironman Member Posts: 7,531
    Holy Guacamole

    We have a lot of red clay here in VA, but I've never seen anything like that happen. Someone's gonna pay.



    Mark,

    Is Bentonite similar to red clay? Do you know if it's found in the mid-Atlantic states?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    According to this report....

    YES, and in PA as well...



    https://www.libraries.psu.edu/content/dam/psul/up/emsl/documents/bulletins/bulletin5.pdf



    Keep it dry put there....



    ME

    There was an error rendering this rich post.

  • Rod
    Rod Posts: 2,067
    Kitty Litter

    Bentonite can absorb water 10 times its own weight and can swell 16 -18 times its own dry volume. Kitty Litter and the absorbent stuff you use to pick up oil off the garage floor is bentonite.
This discussion has been closed.