Buried Piping With Live Surface Loading

Posted by: marchie

Buried Piping With Live Surface Loading - 10/14/19 02:31 AM

Hello.

Is there a procedure on how to simulate or input a live surface loading from vehicles on the surface for a buried pipeline? If there is, how?

Regards,

Marco
Posted by: Michael_Fletcher

Re: Buried Piping With Live Surface Loading - 10/14/19 12:04 PM

Not codified, that I've seen.

But I suggest you start with the Spangler Stress Formula. There have been proposed modifications to it. It covers hoop stress.

As for bending stress, as a CAESAR input, I've calculated the increase in area distribution of the load as a function of the angle of repose for the material and depth, which reduces the load distribution, but increases the length of pipe affected.

You'll want to consider distance between axles for purposes of overlapping loads frustums through the ground.

I would advise putting in various safety factors due to the inherent long term unpredictability of roadwork lifespan and potential idiot driver overloading the road.
Posted by: marchie

Re: Buried Piping With Live Surface Loading - 10/15/19 12:48 AM

Thank you for the response.

Actually, this is my first to analyze an underground pipeline crossing a road. So how to simulate the effect of that load in the CAESAR II? I really do not have any idea. Do I need to impose a Force, F on a node crossing the road? Thank you and please enlighten me.
Posted by: anubis512

Re: Buried Piping With Live Surface Loading - 10/15/19 05:34 AM

You could use an external force at multiple points along the road or you could use a uniform load vector for the applicable elements; likely in F/L instead of g's.