How to Calculate Actual Compression Stresses Acting on the Buried Pipe

If you do not mean radial stress:

Axial stress might be the difference from conditions when buried compared with running conditions: mainly temperature. So you would be looking for stretch or compression due to temperature changes.

Thank you for your reply! May i know is there any formula for that radial stress ?

Yes. Carry out a force balance on a longitudinal section through the pipe. It's only arithmetic.

One way to consider the compressive stress on the pipe is to use a hypothetical fluid of the same density as the surrounding subsoil and cause it to act uniformly on the pipe outer surface.

Of course the outer stress is compensated by the stress caused by the pressure of the contents.

Thank you for your reply !

Thanks

This is a civil engineering problem.

Is it not the weight or load of the soil with in the cross section along the horizon?

yap! this is civil engineering problem but i found out somewhere it can consider with axial stress also in order to calculate the critical buckling stress of a buried pipe.

I concur. There is no model that could possibly be accurate enough to simulate your actual situation, although you might get order of magnitude estimates, by considering the type of fill material, grade, flow conditions, anchoring of the pipe, etc.

Why are you suddenly asking this question? Were put in charge of a pipeline after it was built, after a failure? Are you a regulating body representative performing an audit on a pipeline company?

We would enjoy having more information on the precise situation involved, as some of us here could probably give you a better answer as a starting point.

Thank you for your reply ! I understand that actual ground implementation is very different and challenge but i am just started study of designing the underground pipe laying.

I realized that it is not a easy going calculation but i need to figure out the critical buckling pressure of a buried thermoplastic pipe (eg: PE100 pipe). This is my new topic and i am from mechatronic background. So all the usages are very strange.

One way is to carry out a practical test:

https://www.youtube.com/results?search_query=rail+tank+car+implosion

Another way is to ring the pipe manufacturer, and ask.

Why would buckling pressure be more of a focus than crush pressure? You cannot guarantee in any such situation the pipe will always be under pressure.

Buckling pressure will have so many variables, makes me think you need to find out if lines such as the one you are focusing on are buried with a slight tension on them.