Thrust block in buried piping

I need to provide in Thrust block I.e anchor blocks in buried piping. But when I model the anchor in Caesar buried piping model, the anchor is ignored as it is in the buried portion. I would like to know how I have to model the thrust block for the buried portion. I have to consder the thrust block section of piping as above ground piping or any other method?

As you have discovered, CAESAR II removes all restraints in the portions of the piping that you bury.

Once that's done, just add the anchor to the buried model - anywhere you want.

When we model concrete thrust blocks in underground piping we get our geotechnical engineers to calulcate 'soil stiffness' values for theconcrete thrust blocks and then enter these in the buried pipe modeller.

I am doing pipe stress analysis for chilled water piping which is buried nearly 1.5 metres below ground in a desert in Middle east. In the caesar buried piping model,when I input the thrust block as anchor, with default caesar stiffness, I get very high forces (as high as 100 Tonnes). What is the realistic stiffness values, I have to use for thrust block which is in buried portion. Can someone give realistic stiffness vaues for anchor or equivalent soil properties for similar desert conditions.

Similarly for road crossing, where the buried pipe is encased in concrete, what are the soil properties to be used?

we have done a lot of work in this area and I agree with ITCHY "we get our geotechnical engineers to calculcate 'soil stiffness' values for the concrete". This is not always possible or easy especially at the outset. Typical range of values we have found start around 50kips/in varying more typically up to 200 kips/in and up.
Here in the north we have frozen ground case which MUST be considered!
NNNB.. must EXERCISE EXTREME CAUTION since these are not universal and there are many variables and scenarios which greatly affect the value to be used....EMPHASIZE useful for first "cut" only.

What I do normally to overcome high trust loads;

- minimise the wall thickness
- minimise the diameter
- add expansion loops

These make a difference..

Regards,

Dear friends,

1-Should I enter soil stiffness at thrust block in spreadsheet or buried pipe modeler?
2- If I don't have soil stiffness(lateral, axial , downward and upward) at thrust block, how I can estimate stiffness and ultimate loads?
3- As we know, thrust blocks need some movements(for example 1 inch) for activation . How can I consider this movement(without exerting load on piping)?

Reminder

If I add the anchors into the buried model, then they have to be re-entered every time I create a new B model (change original piping configuration or change soil properties). Is it possible to add thrust blocks to the buried pipe modeler somehow? Change the soil stiffness to stiffness of concrete?

No, you would have to make this modification to the "buried" model.