Advice on concrete collar

[GaryMoz]

Hi all,

I'm finally trying to get the wheels is motion for building a pond.

The pond will be around 25000ltr and be used to keep mixed fish. The pond will mainly be sunken, but there will be some above the existing ground level, to one side of the pond there will be a raised patio (this is at door level of house), there is also a bog filter to go with it.

Originally I was thinking of using concrete blocks to build the sides of the pond, but I worried that the price will get out of hand. Now I considering using a reinforced concrete collar. I had thought of making the collar then laying a couple of layers of blocks on it to make up the height, But it may be cheaper, quicker and better to do a taller collar (I've done it tapered to reduce concrete but it can be straight).

Note: the patio on the left will compacted hardcore, not hollow as the image shows

Max depth of pond is 1350mm, The soil is clay, I intend to use a boxed liner.

So, would this work and would it be cost effective compared to footings and blocks laid on side?

Would the collar need to go on compacted hardcore? I feel the inner edge of the hard core would be weaker than the clay soil?

Would the order of construction be, build the collar first and then dig put the pond? I would imagine a digger would be needed to dig pond, I don't want it damaging the collar. I will probably get a groundworker in to do the major landscaping of the pond. The pond will be be built in heavy clay soil, which is currently covered in concrete, so this will have to be removed first.

 

[GBBUDD]

the way you have the bond beam tapered away from the water area you should also do on the the water side as well and continue the earth on an angle as well . the way you have the edge of the bond beam on the edge that drops into the depth can work but you need perfect soils . so instead of risking collapse or failure . id bring the bond beam in a foot from the edge. Vertical earth walls fail much easier then will a tapered wall.

 

[GaryMoz]

the way you have the bond beam tapered away from the water area you should also do on the the water side as well and continue the earth on an angle as well . the way you have the edge of the bond beam on the edge that drops into the depth can work but you need perfect soils . so instead of risking collapse or failure . id bring the bond beam in a foot from the edge. Vertical earth walls fail much easier then will a tapered wall.

Thanks for the advice.

I intend to use a boxed weld liner and i believe they need vertical sides

 

[GBBUDD]

They can make they to any angle it's all in how good your company is in making it. but again if you have a class b+ soil you maybe ok other wise you'll want a concrete wall

 

[GaryMoz]

They can make they to any angle it's all in how good your company is in making it. but again if you have a class b+ soil you maybe ok other wise you'll want a concrete wall

I don't believe we use that soil classification over here in the UK. But the pond will go in heavy clay, which looking at the classification in the USA it will be Class A or B. So think should be good for near vertical sides.

I may go for concrete block walls, but it all comes down to cost.

 

[GBBUDD]

Cinderblock walls will be there 25 to 50 years done well. Done right 100 to 200