Design of gravel cover for 32" HDPE Pipeline

[drakkkko]

Hello,

I need to model in a suitable program, a continuous filling of gravel that goes over a HDPE pipeline about 2 mile long.

I have at least two ideas to do this modeling.
1- Design each node with a simple support and a guide with loose gravel stiffnes, spaced every 7 ft.
2- Modeling as buried pipe.

I already tried the second model (buried) and the problem it becomes very rigid and does not pass B31.3.

Can you please advise me?

 

[LittleInch]

B31.3 is a piping code not pipeline and doesn't handle burial very well. Also 2 miles of PE pipe will be fairly stiff. And thermal expansion of PE is high compared to steel.

What are your process conditions?

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

 

[drakkkko]

Dear LittleInch,

Fluids : Brine
T°Min/MAx = -2 °F / 79° F
Pressure = 337 Kpa

I'm modeling a continuos berm (as you correct me in another question) of gravel. So buriel a reliable model ?...maybe taking some discontinuous gravel stiffnes is better model....

 

[dhengr]

Drakkkko:
LittleInch will know the HDPE pipeline details much better than I do, but, I’ll bet that gravel is not the best soil material for bedding and immediate fill around HDPE pipe unless it is very carefully graded. I would think you don’t want any large rocks, boulders, or any sharp, crushed rock anywhere near HDPE pipe.