I am doing a stress analysis for an underground piping. I added an anchor to the pipe. The calculated axial force is 300,000N. I think this is too high. How to model the underground piping to make it right?

Thanks,

The CII user manual has an excellent guide on how to model buried pipe. Make sure you have read that and understand it first.

Have you got the correct soil data etc?

The soil is clay type (.02MPa shear force, 2000kg/m3, 17degree friction angle). The pipeline is buried 3m below the grade. Anybody know why the anchor force is so high?

No one will know why the anchor force is so high except for yourself, are you talking about an anchor in the buried section, or is it above ground near the soil penetration. There could be many reasons, such as:

- cold / hot piping (ie: high delta T) with insufficient flexibility in a stiff soil type
- incorrect modelling
- slug / surge loads

Is your pipe of welded construction, or is it made of push on joints? Do you even need an anchor? You do not have to worry about rack space, and if there are no surge or slug loads, then for welded pipe the soil would sufficiently restrain the piping.

I am not suggesting you post all your details of your system, as I think you should review your model keeping in mind the above ideas. If the load is as you say, and you do need the anchor, then I suggest you consult with your supervision and if necessary consider re-routing the piping.

Have you checked with your supervisor for advice?