Storm Inlet Box Construction
Storm Inlet Box Construction
(OP)
I am working with a contractor who is dead set on using CMU blocks to construct his storm inlet boxes instead of casting the walls in place with concrete. He will put rebar in the CMU wall and then fill the interior of the wall with concrete and vibrate. The top and bottom of the box will be standard. I really don't like this method but I thought before I dismissed it I'd see if anybody has positive input on this method. Has anybody used this method before? Is it durable?
Thanks for the help.
Thanks for the help.





RE: Storm Inlet Box Construction
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RE: Storm Inlet Box Construction
I have seen these types of inlet constrtuction used in Europe and in some parts of South America. Durability I would be unsure about but could only speculate that the seams may be may be more prone to cracking overtime vs a cast in place wall. From an aethetics point of view, the CMU blocks would be less attractive.
I would be curious to see what feedback the other members in the forum has.
RE: Storm Inlet Box Construction
Thanks for the response!
RE: Storm Inlet Box Construction
RE: Storm Inlet Box Construction
Maybe you can convince them to use a precast structure. It's a little cheaper, but should last for a while.
RE: Storm Inlet Box Construction
I would be inclined not to allow this if possible, or at least require them to get an engineer to sign off on the design. How deep is the box, and is it in a traffic area recieving loads? If so you could say this is a health and safety issue.
I am not sure the CMU blocks, or the grout between them, will hold up that well against water erosion. I think the CMU blocks are only constructed with fine aggregates which might make it susceptible to eroding.
Lastly, you mentioned this is a private storm system..are you sure? For example will the storm system convey any off site flows, if so it should be considered public with an easement for the other neighbor.
Also, will this system discharge into a public storm system or drainage course (of course it does eventually), then you could claim their design doesn't mesh with the standards of practice in your area.
Is there high groundwater? Make them do a vacuum test, hehe, it will never pass.
RE: Storm Inlet Box Construction
RE: Storm Inlet Box Construction
My biggest concern with a CMU box would be where large magnitude flows turn corners. Momentum is a nasty thing, and rarely considered in storm drain design.
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: Storm Inlet Box Construction