Support for above ground pipe

[ENGIRL]

Hello,
I have to design a support for a pipe above ground. I think rock soil is very close to the surface but I don't know where exactly. So I can't use helical anchors because I might reach rock and to my understanding you I can't use Helical anchros on rock foundation. I tried anchoring on concrete blocks, but since don't know where is the rock elevation , I am not sure how to design the concrete blocks with frost protection. what do you guys recommend?

Thank you

 

[phamENG]

I'd recommend a geotechnical report so you can find out where that rock is and how you're going to support this. If it's a pipe, it's probably important. Unless you (or the company you work for) want to be responsible for loss of water to however many people that pipe serves, or a sewage spill if it's a force main, or whatever else it's carrying...you should be sure of the supporting soils.

 

[driftLimiter]

Seems like if get to the rock and pin your footer into it then thats the best case. If it is exceedingly far away from the surface might need to consider something else.

 

[JStephen]

How deep is the frost line?
If the owner/client is a large oil/gas company, large utility, or large consultant, they likely have standard details for that.
PIP may have standards for it if applicable.

 

[LittleInch]

You proably need to create three or four options depending on the found "rock" level.

"Rock" is a bit vague though. Is this solid rock like granite or rippable fractured rock?

So you need the base of the support to be under the frost level to prevent frost heave so an upside T shape is usually used.

If you hit rock at low levels then have an option where you drill into it to anchor the support.

Or excavate a shallow foundation with pneumatic picks / explosives.

Shallow rock can be seen on satellite images using the right spectral data / radar. Ask your GIS person to see what data you can find on shallow rock.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

Sleeper
Monolithic block
Plinth and spread footing.
Sonotube

But you generally have to know something about the geotechnicals and at least pipe elevation, diameter, contents and span before trying to decide what's best.
Are there expansion stresses?

Otherwise the best you can do is to rely on "Field engineer to decide foundation type."

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[ENGIRL]

Thank you for your recommendations everyone. the frost line is 1.5m deep in the area according to our geotechnical engineer. I don't know the exact type of the foundation. I only judged from some pictures provided by the client.

 

[phamENG]

You have a geotechnical engineer but don't know what the soils are? I'm confused...

 

[ENGIRL]

We are provided only with pictures of the site from the client. No report on the type of soil. And the construction site is 10 hours away from us. We also do not have a geologigst to evaluate the soil just from looking at pictures. I agree that a geotechnical report would have been very helpful.

 

[1503-44]

Go with a monolithic block subject to field verification.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."