Whats wrong with this; stone columns as soakaway?

[ToughButterCup]

We need piles because we're on 'made ground'.

We've chosen to use stone columns instead of steel piles. So far so good.

We need to satisfy SUDS requirements.

 

So, what's wrong with popping (say) four more closely grouped stone columns in our garden to act as a soakaway? No need to compact the stone to 150kN, but we could easily (20 minutes) pop four stone columns in for a few extra quid, and have a soak away.

 

Too simple innit?

What have I missed?

[Guest Alphonsox]

Any reason you can't use the ones you are putting in for the house ? Why do you need to dig "extras". ?

[ToughButterCup]

Erm....... it was, until a few moments ago, an unknown unknown, that's why. So now it's a known unknown, off I go on another assault on the learning curve.

 

More I play this game, the more I know I don't know.

[Guest Alphonsox]

I've just learnt you can create piles using stones instead of steal - completely new to me :-)

[Stones]

Can't see any reason why not given you'll have the plant on site. Assuming four piles gives you sufficient volume to satisfy your drainage requirements, the only consideration I can think of is that the piles would have to be shallow enough to avoid you tapping into / polluting drinking water aquifers.

[Construction Channel]

it depends if they want to make you use "crates" in the soak away, (depends on the building inspector for us)

if they want to you dig a big hole and fill it with stone i don't think in this case they will care if its round or square  

[ProDave]

How high is the water table? Here it's very high so only the first metre or less of the column would act as the soakaway, the rest would be a "well" So there would not me much surface area to do any good.

 

It might be totally different if your water table is normally 10 metres down.
 

[TerryE]

@Alphonsox, you should see Ian's previous YouTube link on this.  I spent about 15mins looking at all of the techniques to pile with stone, injected concrete, the works.  I know that I am sad but I found it fascinating.

[Ferdinand]

Study some Victorian water cisterns. I have not seen a stone one but it should not a problem to have its feet in water.

 

Our small Manor House had one which was like an underground room with an arched roof, under the kitchen garden.

 

I assume it was drinking or washing water. Crystal clear.

 

Or for light relief read how WInchester Cathedral had so much water around its foundations in 1906 that they had a professional diver working in a 4m deep trench for 6 years to underpin them.

 

He was called William Walker. They now have a delicious exhibit in the slightly flooded crypt with a statue by Anthony Gormley.

 

http://www.winchester-cathedral.org.uk/our-heritage/famous-people/william-walker-the-diver-who-saved-the-cathedral/

 

Ferdinand

 

Edited December 22, 2016 by Ferdinand

[Ferdinand]

FOr a Christmas Diversion jump to 5:44.

 

https://m.youtube.com/watch?v=SFXY8sM88q4

 

[ToughButterCup]

9 hours ago, Stones said:

Assuming four piles gives you sufficient volume to satisfy your drainage requirements, the only consideration I can think of is that the piles would have to be shallow enough to avoid you tapping into / polluting drinking water aquifers.

 

So, that's a simple bit of maths, then isn't it? Even I can manage the volume of a cylinder (Pi r squared * h). No need to go below 4 meters (our deepest bore hole_)

 

7 hours ago, ProDave said:

How high is the water table?

 

First thing I did with the new digger was dig a 2 meter deep pit and fence it off. Bone dry since July.

 

So why don't I simply fill that pit with stone?

 

Oh for God sake! There's nowt like making a fool of yourself in public is there?

[ProDave]

At the start I dud a 2 metre test pit (for the structrual engineer to assess the ground) The water level varied from 1 metre down, to level with the ground.
 

[PeterW]

Don't forget the calculation needs doing ... it's 50% of the depth below the invert multiplied by a couple of other things and a doodah...

 

then allow for infill only having 20-30% true capacity... you may find crates are simpler ..!