Liquid Earth

[TomG]

What we are doing is taking down the mound to level out the back yard (hard to see in the first picture) and to do this we have to demo the sides of the old pool down about 2.5' Who ever originally demoed the pool did a horrible job, the old cement walls were only 2" below the grass, and they didn't punch holes in the bottom of the pool, thus creating the "liquid earth".

What this is, is someone filled in an old in ground swimming pool with clay and didn't punch a hole in the bottom to let any surface or rain water escape, so over time the clay became extremely saturated. When I drove the mini excavator over it the clay began to "pump" or liquify and this is what happened. I have seen soil liquefaction before but never to this extreme.

This is one of the coolest things I have ever seen on a job. The dirt was literally moving in waves as you can see!

Also you got to love the commentary from my employee who was filming.

http://www.youtube.com/watch?v=6zGsujlR4fY
http://www.youtube.com/watch?v=Rd6W2aP2dkA

[kreft]

where the pics of the new dump?

[TomG]

Originally Posted by kreft

where the pics of the new dump?

I totally forgot to update that thread with pictures, I'll get some up tomorrow.

[knox gsl]

How far before hitting water?

[minimax]

The mini-x is saying please grease me!!!! in the video,

minimax

[Dirtman2007]

I built a pond dam one time that was like that. it was fun driving the dozer over it as it rippled like waves. over a few months it dried out and was solid as a rock. its fun none the less. Gotta love the people who dont knock holes in the bottom

[TomG]

Originally Posted by Dirtman2007

I built a pond dam one time that was like that. it was fun driving the dozer over it as it rippled like waves. over a few months it dried out and was solid as a rock. its fun none the less. Gotta love the people who dont knock holes in the bottom

haha yea its funny how some people don't think about making a hole in the bottom... Its a pool it holds water!! I guess this pool was filled in about 10 years ago so you can imagine how much water is in it. The home owner is now considering taking a lot more of the clay out and putting a lot of holes in the bottom.

[Dirtman2007]

Originally Posted by TomG

haha yea its funny how some people don't think about making a hole in the bottom... Its a pool it holds water!! I guess this pool was filled in about 10 years ago so you can imagine how much water is in it. The home owner is now considering taking a lot more of the clay out and putting a lot of holes in the bottom.

what size holes are you putting in? like 1" holes wont do a darn thing you gotta dig the bottom up like I did in the pictures I posted a month or so back if you dont want to have problems like that

[TomG]

Originally Posted by Dirtman2007

what size holes are you putting in? like 1" holes wont do a darn thing you gotta dig the bottom up like I did in the pictures I posted a month or so back if you dont want to have problems like that

The original plan was to put a 3'x3' hole in the deep end. But now the homeowner is still concerned because there is now standing water on top of the clay, so he is contemplating excavating all the clay out and ripping up the bottom like you suggested. Its just going to come down to how much $$$ he wants to spend.

[Dodge2]

thats soo cool. I have a lawn that I mow and it will move just like that when I walk on it. I always wondered why it did that. must be an old pool under it.