Dear all,
Is there any code for the pipe undergroud?Not the oil transmission pipe,just the pipe filled with cooling tower water,buried 4.5 meters below the ground.Because the pipe is very lage,whose diameter is 80" inch,I don't know is it necessary to support the pipe specially.Such as piling,making concrete frusta.If necessary to support,what span is suitable?If not necessary,what my concern is the pipe near the shore,there maybe inconsistent settlement.I think there maybe somebody have met the same question before,according your successful experience,what shall I do?
Any comments will be appreciated!

Help!

The only codes I've seen that address underground (restrained) pipe are the transmission codes (B31.4, B31.8, and Z662).

Buried pipe analysis assumes you have accurate soil data, and you descretize the pipe into a series of elements with soil springs. Because you are attempting to simulate a continuous beam on an elastic foundation (with adequate support for weight loads), CAESAR II sets all densities to zero.

If you are attempting to simulate local soil (support) failure, or other large displacement behavior, you will probably need the assistance of a geotechnical engineer and specialized soil mechanics software. These phenomenon are beyond the scope of CAESAR II.

Hi Rockey

We have carried out underground piping design using B31.3 and also BS7159 (for fibreglass piping).

We always get soil data information from our geotechnical engineers when we do this analysis.

Thanks for all the information.
But Mr. itchy,can you tell me where have mentioned pipe underground in B31.3?I found nothing about it in this code.

No there is no specific mention of underground piping in B31.3 but it isn't listed in the exclusions. We analysis the buried piping to the same load cases that we would analysis the piping if it were above ground.

You may wish to review this previous post
http://www.coade.com/cgi-local/ultimatebb.cgi?ubb=get_topic;f=1;t=000292;p=1#000005

The AWWA have the Design Manual AWWA M11 and other, it could be hepfull for the design of large pipes