hello,
We have a model with buried pipe anlyzed with caesarII 5.20 but in hydrotest case the stress is over range(not allowable).
Note that all densities are zeroed for pipe and fluid for buried part
Can someoine explain this problem
thank you for advance

Read the manual on buried pipe modelling and you will see that CAESAR II sets all densities to zero and replaces them with restraints corresponding stiffness, based on soil parameters and pipe and fluid densities (weights).

The overstress can have different reasons, like differential soil load, inaccurate meshing of the model, and mostly temperature.

Don't worry about the lost densities and check your system for the overstresst areas.

excuse me
but in input it must that i enter 0 for all densities fo buried part or i enter the normal value and caesarII sets them to zero autimatically and replaces them with restraints

First enter the complete system as if it was an above ground system, so including piping and fluid densities.

After that create the correct soil profiles in the buried pipe modeler and convert the model into a buried model. During this conversion CAESAR II sets all densities to 0 and replaces them with restraints.

Read the applicable chapter in the manual, it's easy to understand.

Dear Mr.Corne,

In our project, FRP underground piping of larger diameter 1000ND which it has several burial depth along its travel. that is, the pipe is continously varying its buried depth. In that case, what to do...How to do consider and construct soil model. The pipe is going of 25kms length. Please reply.

Also, I had in this project, FRP pipes of restrained lengths on either side of the Road crossing. How to consider restrained pipes in that area, and Non restrained pipes in other area.kindly clarify.

thanks in advance.

Vertical profiles can be neglected with very small bend angles(~ 5 deg for large diametrical pipes) over short run( ~20m ) within virtual anchor.
Hence it can be skipped.

FRP restrained length :
Non movable length of pipe = restained pipe