Culvert invert repair with concrete

[civilman72]

Designing the repair for a corroded invert in a 15' (fifteen foot) steel plate culvert. I have a few examples from DOT for concrete invert repairs and they seem fairly straight-forward.

I'm trying to figure out if the design thickness of concrete is based on the size of the pipe, size of corrugations, etc. or is it fairly standard for all applications. The design example I have depicts 4.5" thick concrete with two layers of wire fabric and dowels (but this is for an 84" pipe).

Any input or experience would be appreciated.

 

[bridgebuster]

I looked at some materials I had in my files - plans, standard sheets, manual - 3 to 4 inches of concrete above the corrugations seems to be typical.

 

[darthsoilsguy2]

here's a link to a free pdh that discusses this topic

http://www.conteches.com/knowledge-.../rehabilitation-and-relining-of-culverts.aspx

 

[civilman72]

Thank you for the responses. Confirms my initial thoughts. Will be going with 4"-5" thickness.