Dear all,
I'm doing a stress analysis verification for a buried pipeline for ASME B31.8 code.
Pipeline is 16-inch, design pressure 44 bar , design temperature 8o°C and it is buried for about 1 km.
I know that B31.8 consider restrained pipe (button "on" in Caesar) and unrestrained pipe (button "off" in Caesar).
If I model the entire length of buried pipeline, it is correct to consider fully restrained pipeline after the virtual anchor lenght? therefore, I will set button "on" after about 400 m (VAL) from above/below transition section.
Thank you to all

No one can Help me??

Dun worry u will get help of senior person soon.
u know Jiska Koi Nahi Hota uska RICHARD AY hota h.

Thank you for your reply; I hope that a senior stress engineer help me soon.

Piping that is fully "locked in" and cannot move is fully restrained. As such, there are no bending and torsion moments to generate stress and stress can be easily calculated using the code equations for fully restrained pipe. (In other words, you don't need CAESAR II to evaluate fully restrained pipe.) The virtual anchor length provides an estimate of the distance to this fully restrained starting point - both upstream and downstream of the thrust points (e.g. a tee or bend or thrust block).
I would probably double the length of the distance of the pipe modeling the virtual anchoring length in CAESAR II since the CAESAR II axial pipe-soil friction stiffness allows some movement to generate load (it's modeled as a spring).
That code use of fully restrained pipe is an ON-OFF or YES-NO thing but your piping system has a long transition between the two.
So, yes, it the pipe doesn't move, then indicate fully restrained. But I would run it once to see if the CAESAR II model moves first, then update the input as appropriate.

Hello Dave Diehl,
Thank you for your reply; sorry, but I'm a learner with stress analysis and I have some doubts.
If my understanding is correct, when buried pipeline is "fully restrained" the displacements are zero, is it right? therefore, if I set "button ON" on Caesar, I should see no displacements for this pipeline sections in my Output report, is it right?

Coming back to my Caesar model, the buried pipeline length is 1 km approx., then I have calculated the virtual anchor length by hand and I have set the "button On" option after this length, instead I have left all the bends of my pipeline as a "non restrained pipe" (Button OFF). I hope that I was clear,
According to you, my model is correct? How would you build this model?

Thank you

The "fully restrained" radio button simply replaces the stress calculation from the standard "bending-based" formula to the Code's specific calculation.
In my opinion (and based on my limited knowledge of your system), you should not turn on "fully restrained" until you travel more than that virtual anchor length AFTER the last thrust point and turn off "fully restrained" BEFORE you travel more than that virtual anchor length to the next thrust point.

My sistem starts at Launching Trap and ends at buried tie-in point with 16" existing line. The new line is buried after 20 metres from pig trap, there are three cold horizontal bends (one at 70 metres from pig trap, the second 800 metres and the last 900 metres approx.), then there is a tie-in point;
I have calculated a virtual anchor length of 345 m approx.
Then, about your opinion I should model all my pipeline as a "unrestrained pipeline" being the max distance between two bends (thrust points) equal to 800-70=730 metres and not having enough space to set my anchor length upstream-downstream these thrust points.

What is this, 20 Questions?
From what I read, your system is unrestrained.

Ok thank you