ac pipe cover

[john88]

Does any one have information on ac water pipes? The only information that I have is that it is an 8" ac water line, 150psi max./design pressure class. The pipe is under 4 foot of cover.

I want to put in an additional 4-6 foot of soil on top of the pipe. I can calc. out the all the new loading, but I need to know what is the pipe design criteria so I know that the pipe can take the additional loads.

Thanks

 

[jjn]

awwa c401-93 "the selection of asbestos-cement pressure pipe for water distribution" covers loading theory for this material and provides loading and pipe selection curves. hope this helps

 

[john88]

Thanks for the info. JJN

I will get the std. from AWWA.

 

[KRSServices]

I did not realize that anyone designed with AC pipe anymore. Be very careful with your loading factor coefficients and bedding design, if anything, be a little conservative. In my early days, I had the wonderful fun of repairing and replacing miles of AC pipe. The pipe is very susceptible to stress and strain and has very low elasticity properties.

KRS Services

http://www.krs-services.com

 

[john88]

KRS-Service,

It is actually an existing ac pipe that I want to put 2-4 foot of extra fill over the existing 4 foot cover.

Since no one that I know is designing or even manufacturing ac water pipes anymore in the US, the design criteria for max. cover and loading is kinda hard to come by, unless you happen to save an old catalog.

It is an old pipe (1960's), so I definite appreciate your advice to be on the conservative side.

Thanks

 

[KRSServices]

Be very careful. I tried this once with class 200 ac (thicker walls) pipe. We were modifying the road cross section from a rural to urban (curb and gutter) residential. The subgrade was a clay/silt material and the new base consisted of compacted gravels. When packing with a vibratory drum, the contractor ended up popping that main all over the place. In your load calculations, consider the impact that vibratory packing will have on the pipe in terms of vibration and loading. You may wish to spread the loading of the new material with a geogrid material and static roll.

KRS Services

http://www.krs-services.com

 

[Maskman]

be careful if it is 1960 pipe. you dont write down the length of the area and if it is less then make sure to add this additional fill by providing slab on this pipe .

 

[PECPESC]

The conservative route would be to replace the AC pipe with a pipe of contemporary material.

 

[boo1]

Pay me now or later?

 

[dicksewerrat]

Pay me now AND pay me later.