culvert lining mixture

[hwy3dig]

Specifications often require the mixing of round river stone with native materials at the invert of stormwater culverts. Does anyone have a standard ratio of mixing these items?

 

[LCruiser]

Do you mean in the culvert or at the outlet? I've never heard of mixing the two. Why would you do that?

 

[hwy3dig]

This mixture is in the culvert. The Ministry of Fisheries often ask for the invert of culverts to be lined with native material and/or stone, to protect the aquatic life from the abrasiveness of the culvert material. The outlets here in Ontario Canada are generally Rip Rap material.

 

[LCruiser]

Okay - I've never heard of that, but then out here in the desert SW we don't generally put in culverts that run all the time.

To your question though, it would depend on the gradation of the "native material", potential velocity, culvert material, etc.

 

[wmharding]

If I understand what you are asking, the answer is it should match the existing stream bed as close as practial. Hope this helps