Minimum rcp cover 1

[roberttx]

Hi,

Due to r.ow. limitations, we cannot raise the pgl for a highway project under design. However, I read somewhere that you need to have a minimum cover on rcp culverts for arroyo crossings in the project. Does anybody have any idea what's that minimum cover? We're proposing class iv.

Thank you,

Roberto.

 

[cap4000]

I strongly suggest you get the Concrete Pipe Design Manual and ASTM C76. It will have everything you need. If you provide additional info regarding dimensions and elevations
of your conditions I may be able to give you the min cover.
Don't rule out Class V if things get real tight. Good Luck.

 

[roberttx]

Hi, cap400:

Thanks for the reply. We have a couple of rcp circular culverts, one 24" and one 36" located in different arroyos crossing this rural highway. Both culverts only have 2.5" hmac and 8" crush stone base over them, that is 1.05' cover. The pipes are laid out on regular ground and the fill is surrounding and over the pipe. I would like to know if this is sufficient for the class iv pipes to support the hs-20 loading over them and if we should change the class.

I really appreciate your help, thank you.

Roberto

 

[cap4000]

Proceed with extreme caution your Hot Mix Asphalt Course I would consider to be flexible and only as a FILL layer. Your total cover is only 10.5 inches not 12.5 inches as you are indicating. Without going into detail, your major problem will be when two HS20 trucks pass one another!! My Prescription: Seriously look into Class V and a concrete cradle arch over the pipe than your blacktop course. Contact your pipe manufacturer and get the D-Loads and Ultimate Loads prior to cracking per the ASTM C76 Spec. Definitely an "accident waiting to happen". Be careful. Good Luck.

 

[roberttx]

Hi, cap400:

I am sorry. It's 2.5" hmac and 10" stone crush base course.
I will look into your sugestions, thank you.

Roberto.

 

[dicksewerrat]

Go to the D wall pipe.

 

[roadspecialist]

a class IV wall B RCP crossing the road would need at least a 50cm cover on top. as suggected by cap4000, try to refer to ASTM. I would not place coarse aggregates anywhere in contact with the pipe. use of selected earth fill would provide a better cushion aggainst abrasion of the culvert barrel.

 

[gibfrog]

Have you considered oval RCP? You would get a few more inches of cover.

Clifford H Laubstein
FL PE 58662