Loading in Pools

[jjeng2]

I have some potential work with a pool contractor. I would be submitting re-bar drawings to local building departments. Off the top of my head, I would look at a pool like this.

1. As a series of retaining walls(If the pool was empty)

2. With fixed soil pressure and varying interior hydrostatic pressure. I would consider all cases depending on depth of water.

Are there any other loads such as hydrodynamic?People in pool? What about special considerations? Concrete mix design considerations? Does ACI put anything out on this?

 

[SlideRuleEra]

As a supplement to your item #1, be sure to consider the possiblilty of and entire empty pool "floating" out of the ground (high water table). Where I live, it can happen.

http://www.SlideRuleEra.net

 

[jjeng2]

SlideRuleEra,
Good point. I will consider it. I dont know how much geotech considerations I have to give. That is another question. Do I disclaim that all geotech considerations be handled by a geotech engineer? What geotech considerations are there? Settlement? Consolidation(even though I doubt I will have a soil report)? Ive never seen a post on this before. Maybe we can all figure out how to approach it together so there will be a thread for reference.

 

[jhardy1]

Re: Empty pool floating out of ground

In Australia, it is normal practice (possibly mandatory - I'm not sure) to put a relief valve in the low point of the floor, and to provide a gravel drainage blanket (gravel or similar) around the shell, so that if the pool is emptied and there is a high water table, water will flow into the pool through the valve, relieving the uplift. This is certainly a LOT cheaper solution than providing adequate uplift provision for a typical backyard pool.

 

[SperlingPE]

I have been involved in a couple of projects where indoor pools were a part of the building. The pool contractor provided the design and did the installation. The pool shell was a lot thinner than I would have designed using retaining walls. The concrete mix design was very "flowable" and used fine aggregate. I can look to see if we still have the concrete mix design submittal.

Geotechnical considerations have all been touched on in the above responses; allowable bearing, lateral pressure, water table, consolidation.

Consider sub-base and what will be the drainage system behind the walls.

 

[miecz]

ACI Publishes "Code Requirements for Environmental Engineering Concrete Structures", ACI 350. While a pool does not technically fall under ACI 350, I would design it as such. Rather than a series of retaining walls, you might consider designing the pool as a tank, designing for corner moments.

 

[mshimko]

From a homeowner's perspective only (I'm an engineer, but not civil or geotech): in the southern US where the water table is high, the common practice is to pump-out the ground water locally during pool construction. The same thing is done during maintenance or repair when the pool must be emptied.