Pool Dig - Struck Loose Gravel

[Corban987]

Hi

During the dig of our DIY pool we have struck gravel, the gravel ranges from Pea Gravel to large rock the size of 2 fists all mixed also with some clumps of clay, when wet it moves easy, ie when I stood in it I sank about an inch as the gravel displaced around my feet. Now that it has dried it is fairly hard. This goes for about 1/2 the width of the pool to 1/2 the length of the pool. I didn't dig most of the hopper because of this, but now that it is dry I can finish off by hand (not looking forward to that) the rest of the deep end. The shallow end was solid clay the full width - so no issue there. It looks like the half end that I chose for the deep end was back filled many years ago as I also found broken bricks etc.

So now that I have a huge hole in the yard, is this gravel mix an issue, can I construct the pool on top of this? I will have this inspected by local authorities on Monday so would like it fixed by the inspection if possible?

Other than that the dig went fairly well, a little leveling but not too much, hopefully the kit will arrive this week and the inspection goes well I can start putting up the walls this weekend and bolting it all together.

Thanks for any help.

 

[pwrstrk]

If that's a hole that somebody buried junk I'd dig all that out and see how deep you are in relation to how deep you want it to be. If its deeper than you want then you can bring it up with some crushed stone and compacted in lifts.


Sent from my iPhone using Tapatalk.

 

[4knights]

Possibly an old oil tank that was removed and the hole filled in with gravel? County records would show any permitted work done on your property.

 

[Corban987]

I dug down the 6 feet already - its all the same. I think it is just fill, as we live in the edge of a slope, I think the slope was filled on the side to give some more area in the back before it goes down. I need to build a retaining wall as well. When you see the pics you will get a idea of my description.

I will post some pictures in about an hour.

 

[MassNerd]

It's not your septic leech-field is it?? :?

 

[Corban987]

Here are some photos.
the corner where the rocky gravel is, with a zoomed in shot so you can see the type of fill used - very deep with some very large rocks, I couldn't drive pegs into the ground here due to too many large rocks.

 

[Corban987]

Definitely not my septic, that is on the side of my house. (so I was told when I bought the house - plus can see the blocks that mark the top inspection points)

 

[4knights]

What about a very wide shot? You said its on a slope that was filled, do you know how steep a slope? That will make a difference in how deep you have to go to stabilize the retaining wall.

 

[Corban987]

Here sorry, only let me upload the three, so I just left it there.

 

[JamesW]

It's hard to tell for sure, but that slope looks like it might be a problem. You might want to get an engineer's opinion on a proper solution to make sure that everything is stable.

 

[Corban987]

The retaining wall people coming this week - there was one there previously but it was all rotten and eaten by ants. Wanted to replace it with concrete

 

[4knights]

Definitely want an engineer on this one!! That slope with any form of ground water or even rain runoff could be disaster for the pool (and anyone in it, if it let go)
Not saying it can't be done, Ive seen very nice concrete retaining walls at were 30ft tall.
My parents have a 15 ft tall retaining wall made of tires that has held for 40 years. (man that was a pain packing dirt and rock into those things!)

So structurally it can be done. Just want to make sure it's engineered and the builder has a great warranty.