Dear Friends,

I am doing buried analysis for 24" CS PE lined launcher reciever pipeline

I have calculated stiffness values at 800mm and 1500mm cover.
I have checked on "FROM END MESH" at the first node of buried or AG/BG point and then checked on "TO END MESH" whenever the soil stiffness value changes. I also have flange pits which i have considered unrestrained and put soil model no. zero hence i have not checked in FROM END MESH or TO END MESH for pits.

My question is whether, "we have to always check in and check out whenever soil stiffness value changes though model no. for different soil stiffness remains same i.e. Soil Model No.1" or "Once we check in at FROM END MESH then directly we have to check out just before the node at which Soil Model No. is ZERO".

Please give your suggestions.

Hi:

Any ideas how to solve this? I have the same issue.

B. regards.

LFC

Hi,

I am studying buried piping right now and at I'm a little bit puzzled with that also. But after reading Caesar II guidelines for UG piping, I found out that in checking the FROM/TO end mesh we are declaring the element to have a lateral movement. This is Zone 1 and notice that Zone 3 is for bearing span lengths for axial displacements only.

So as far as valve or flange pits are concern, I think it is still up to the user on whether or not he will treat this points as Zone 1 or Zone 3.

Like for example if a valve pits is constructed along with the straight run of pipe. I would not take time to check for the FROM/TO end mesh since most likely it will not deform laterally.

Also note that when there is change in soil properties other than near your lateral bearing span it is advised to check for FROM/TO end mesh, since this point will also affect your lateral bearing displacements.

This is just must opinion and interpretation of what I have read.
Please advice if there's any wrong idea on what I stated above.

Cheers,