Upheaval Buckling

If the pipe is fully anchored axially, the pipe cannot change in length. An increase in the temperature of the pipe will produce compression throughout its length. Since it cannot expand axially, it will buckle unless continuously anchored laterally.

Hey Bruce,

Why laterally? Why not virtically? To buckle does the length not change?

Chuck

It will buckle in a direction normal to the axial direction, which is what I mean by laterally. It will buckle in the direction of least resistance, in this case, probably vertically, but it could buckle in any direction at right angles to the pipe, whichever has the least lateral resistance.

And, yes, the length does change as buckling proceeds. A pipe which was in a straight line and axially compressed is now in an arc and stress relieved. The length of the arc is greater than the length of the straight line so the length has changed.

Bruce,

Have you ever heard or been involved with upheaval buckling of properly buried onshore pipelines? I

Chuck

Chuck,

I have never been involved with the problem. Prior to reading this thread, I had not heard of upheaval buckling, but it seems to be a very real problem with undersea pipelines. Here are a few sites with more information.

Bruce,

I have looked at a few of these sites. I am concerned more with onshore pipelines.

There is a paper by K. Peters - About upheaval and lateral buckling of embedded (buried) pipelines - that discusses new methods of analyzing the onshore problem.

We have in the past used the criteria developed by Palmer and Associates and to my knowledge this has been successful.

I have been in the pipeline industry for a long time and havent seen onshore biuckling and therefore I wonder if the new theories developed by Peters are justified. Very impressive - second order solutions.

Chuck

Chuck,

I am not familiar with the Peters theories, so I will not comment on their justification but the critical buckling load of structural members has been known for many years. In the mid 18th century, Leonard Euler developed a theory which accurately predicted the buckling capacity of a member of known properties and known length. His work is still studied in engineering schools today.

In the particular case of buried pipelines, I am not clear why second order solutions would be necessary. But that is likely because I do not understand the issues. It seems to me that buckling could be prevented by anchoring the pipe to the ground at discrete intervals.

hi bruce

we have 8in gas producer pipeline lenghth 8 km- X65 AP onshore has exhibit axial movement and had been ruptured on stand by mode and has heavy condensate at the rupture, the pipeline exhibits upheaval buck and has been shut of. it has stopper and not Ancholer at the X-tree the rupture occurs 1.74 km away from the X-tree where the pipeline will tie in to Remote Mainfolds prior to go to central degasing station

please help as we are now doing analysis and recommendation?

Dear Chama,

I am working on project requiring upheaval buckling analysis to be done as per technical paper by K. Peters - About upheaval and lateral buckling of embedded pipelines.

But I am not able to locate its source to get it.

Would you please share this technical paper?

Thanks

DSL

Dear DSL

i am a specilaist to do the calculation based on Dr. K.Peters technical paper, and have developed a mathcad based program to do these calculations.. i can also generate the graded profile for avoiding upheaval buckling based on these calculations. My software is already approved by ADCO (the client who introduced this requirement for all their buried pipelines). You may pl write to me on <email removed>

KKV

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Dear member,

Could you please send me the mathcad programme, I am a MSc student and doing some work on upheval buckling.

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Any bhelp will be much appreciated

Dear KKV,

currently i am working for an onshore project for ADCO, it will be helpful ,if you can share the mathcad sheet for upheaval buckling.

please locate kk vijayakumar in linked in to see the details of upheaval buckling....kkv

pl go to linked in and locate kk vijayakumar for details of upheaval buckling calcs.....kkv

Hai KKV,

can you share to my email regarding upheaval spredsheet which has you made?

Thanks

ARS

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pl go to linked in and locate kk vijayakumar for details of upheaval buckling calcs.....kkv

pl go to linked in and locate kk vijayakumar for details of upheaval buckling calcs.....kkv

hey chuck,

recently we did an onshore pipeline project in which upheaval buckling calculation was done

Hey Ben,

We do them as a routine on all our onshore pipelines particularly if the product is hot.

Chuck

Hey Chuck,

yea,

chuck, r u using K peters paper for upheaval clacluation?

what are the main things while doing the followings:

1) stress analysis modelling ( steady state and transient analysis)

2) Slug analysis and modelling

3) Metullergical analysis

second L

what is the function of the BERM over the pipeline (GAS) as we used to lower the pipeline after welding to the ground, at a depth of 1.2 meter and on top of it we make one meter of the BERM (CIVIL) so the total length 2.2 is this will prevent upheaval buckling? what is density of soils does it has effect?

we have done magentic survey for the above pipeline as it does measurement from the top of the buried gas pipeline to the top of the BERM and we correlate the result with AS built final drawings (after construction) and the magentic survey and we subtract the top of the BERM to the as built co-orinate and berm top with the magentic survey points along the complete profile of the pipeline we have found that some locations exhibits 1.6, .4 meter, 1,8 meter. .78 meter -- for your information the magentic survey has performed at each 50 meters ( and each pipeline length is roughly 12 meter standard, we are now going to take some samples say 10 points 6 unaaceptable and 4 acceptable and we will make survey trail pit excavation for these points to check the accuracy of the survey., however, one engineer points out that to make it accurate we shall re-make the magentic survey for each 3 meter rather than 50 meter at these selected points? what do u think.

and what will have these unaccetable depth in the upheaval buckling? how to prevent this as we have already pointed in our specification that contrcator shall install ancholer but at the site it is stopper at x-tree, what are additional measures to prevent buck due to thermal so the rupture can nt occur? does expansion loops help and where to install it am project manager

This is a very specialized subject and definitely beyond my competence to answer. If you have not worked on a similar project in the past, retain a firm familiar with upheaval buckling to work with you until you develop a clearer understanding of how to approach the problem.

let me tell ée whqt I do to qvoid buckling. first during installation I use loop or ben about each 800 meters this to reduce axial force and displacments , after that the model is use i caesar II , for analyse loads and stress , at this level everxthing are OK , but the upheaval buckling I use formula from B31,8 and in books , but I am not sure that is right because I compare all of them I found big differcence, there is one sampe calculation to known . soil density and to compare with uplift resistance I am not sure that is right ... if yu want to avoid bucking add heavy roc on the soi excavted....I do this every time I am sur that is several formula but sorry I don't have documentation regards