Hi Richard and Dave,
Do you know any way to present pipe enlargement (valve )axial restrain in buried pipe?
I am modelling valve connect to a tee branch side, and the valve(CSO), tee and pipe will be fully buried in soil.
a straigth pipe connected with valve, the axial movement of tee branch direct is big.

since valve body is even biger than pipe diameter and restrain conditions are also different, because cross section of valve is square, but pipe section is circle.

how can I model restrain on valve body?
Can I use beam element or pipe element to present valve body?

Thanks
Limin

After burying the model (where CAESAR II re-meshes your system), just edit the buried model and apply your axial restraint.

Thanks Richard,

How can I define and modify the restrain on valve body? specially in axial direction of pipe,
CII calculated axial restrains of pipe are based on friction between pipe wall and soil. but valve body (face) will fully against with soil, this will cause much higher restrain compare to friction that pipe will slip with soil.

After CII convert base model to buried model, can I modify valve axial restrain as LIM with or without gap? or LIM with stiffness? but how big stiffness number should be used?

Best Regards,
Limin

Yes, after the burying process, you can modify the restraints. At the valve you would apply the LIM as you state above. How big should the stiffness be? I can't answer that question, it will depend on the area resisting the axial movement and the soil stiffness.

Hi Richard,
Since stiffness of soil against with valve body very hard to get,
May I model valve body using pipe or beam element and with pipe buried depth +/- 1/4 valve total body height? this way will let CII to calculate soil stiffness acted on valve body.

Thanks
Limin

Yes you can try that. Compare the results with and without the valve body to see how sensitive the results are to your assumptions.