Above ground concrete pond..advice needed!!!

[Brutuscz]

This pond was built by a fellow koi-bito member. It is also below and above ground. They are simply interlocking bricks. No mortar or anything. Also, nothing but a solid ground...no concrete collar or anything special laid down first. I have been told they have had no problem with bowing, shifting or anything. This is what I originally had in mind.
Regenmeneer...what can I do so I dont have to worry about ground collapse?
I also think I will use the 16X8X8 blocks instead of the 6" ones. I have found the larger size locally...so I will go with them.

[Steve Nguyen]

since your pond will be a lot bigger than this one. there will be much more pressure of water load. not sure if similar setup with no mortar will hold up.
also, from the pix, looks like solid blocks were used. it has more weights density so it hold up more than the hollow 16x8x8 cinder blocks. I assume you are using cinder blocks. anyhow, if I was you, I would use mortar to keep them together.

Steve

Quote: Originally Posted by Brutuscz This pond was built by a fellow koi-bito member. It is also below and above ground. They are simply interlocking bricks. No mortar or anything. Also, nothing but a solid ground...no concrete collar or anything special laid down first. I have been told they have had no problem with bowing, shifting or anything. This is what I originally had in mind. Regenmeneer...what can I do so I dont have to worry about ground collapse? I also think I will use the 16X8X8 blocks instead of the 6" ones. I have found the larger size locally...so I will go with them.

[luke frisbee]

Steve,
What you said sounds right but ain't right, Water presure is directly related to depth not total mass

[Steve Nguyen]

Luke,

that ain't totally right either. can you explain how the New Orlean levies broke? people said the water pressure has something to do with it but they could be wrong. remember the true depth of the water around NO were a lot deeper than the ground level to the top of the levies. it's like what being considered to build here.

liquid mass exert force in all directions. the bigger the mass, the stronger the force.

Steve

Quote: Originally Posted by luke frisbee Steve, What you said sounds right but ain't right, Water presure is directly related to depth not total mass

[junglegeorge12]

I saw a documentary based on the army engineer's thoughts about how the levie broke. In one location I think they felt a pole or somtehing else fell on top of the sand bags and the water started ruching thru right there as ity made a foot or tow dent, and that washed out the rest of it quickly. In another spot if I recall, they felt the water current outside the levie washed away the dirt foundations holding it and started slamming cars and other debris into it and some surges, strong currents, and waves finished it off. It has been a while so that may not be perfect recall. I don't think hurricane conditions are a good comparison for ponds. You don't have nearly the currents or sudden waves or surges to contend with.
Here we are expecting to get hit hard with a cane or ten this year. Everyone in the low lying areas are so sick of preparing to try to fight it most of them are planning to board up, put phone poles, structural supporting walls at angles to keep the water from washing the home away, and looking for places to stay up here in the mountains. I hope to have sattelite internet soon so I can send you guys live photos inside the eye. Scientists are also saying the volcanoe in Montserat is causing destabilization that will cause at a fault off the shore a ways here to quake and cause a giant tsunami. Glad I live thousands of feet above sea level. So if u guys here a tsunami hits here and don't hear from me in a while, plz send a chopper.

Exactly how do those blocks interlock?

[luke frisbee]

Good Question Jungle,
they don't interlock to the ones next to them.
they have a half-inch lip on the bottom edge on the backside. That edge is placed behind the block it sits on; thus each level of block is a half-inch further back than the level below it.

[junglegeorge12]

So it sounds like they would need to be perfectly level, and how much force they can tolerate would depend on the bevel on that lip. If it is beveled so the lip slides the two blocks together more with more force, it should be pretty strong, but if it isn't, it could be touchy and only able to hanlde so much pressure. How much could be a dangerous guessing game. If you like those blocks why not use a little mortar to be safe?

[mitten]

Brutus-

Make your pond depth at least the depth of the frost lines. "At least" means "or more". In my area that is 42". Your depth requirement will be similar. Find out from the city or just grab a grubby guy at Depot and ask him. (Or girl, of course. This is a modern world I've been transplanted into.)

The tall wall seems awkward to me. I prefer about 20". The appearance still feels like a fish pond with that height of a wall rather than like a water tank. The higher you build your wall the greater will be the likelihood that the wall will fail, so if you want high walls don't also gravitate to the "easy way" of building them. See? Inverse relationship?

Being an old fat guy I believe in things like concrete. It is a great way to give yourself a stable, level starting point. It also causes the wise, or previously scarred, among us to plan a little better because it is such a permanent and heavy material to work with. You will find that many of the most dedicated hobbiests, the folks you love to read here and elsewhere, also have the most concrete in their ponds.

Follows a pic of diggin after the concrete collar and block courses. You can minimize your work inside a hole by doing it this way.

Mickey the windowman

[Brutuscz]

Thanks mitten, I have been considering my planning lately. Changed the plans. Too afraid a 3 foot wall will cause the hole to collapse. I'm going 44" deep and a 16"wall. Then a 2" caping stone. So, only 2 blocks (16X8X8") high. So, still a total of 5 feet deep. A two block high wall should be a lot easier to build. I Hope!!!

[greg]

Brutuscz,

Thought i would post some build pictures of my pond via a link to another website. Pretty similar above / below ground pond you are thinking about. 3000g only really functional not done any landscaping / decking yet as spent funds adding a small collection of Koi to the pond.

http://www.koivista.com/display_seri...&page=0&id=123

Also,

a picture of my friend Pauls pond which is even higher out the ground with a 1m square viewing window. Paul decieded to use a concrete ring beam around his to add strength. You can see the shuttering around the pond top in the photo.

I will add from a persoanl point of view - why take a chance on wether it will hold? Make sure it does!!!