Hi,

Somebody could help me to model a Windrow or Earthern Berm pipeline (I dont know the common name in english for this configuration).

The pipeline is above the ground but covered by 0.5 meter of selected soil.

The pipeline configuration is similar to picture below.




I don't know how to model this configuration in Caesar II, the underground modeler not consider this.

Somebody has already modeled , somebody has worked with this configuration?

Thank you!

From a stress perspective, treating it as a regular buried line would provide more resistance and thus result in higher stresses.

It'll be mostly accurate for long straight runs, but more conservative around bends, to which they either need to bulk up the earthwork or expect the movement of the pipe to break it up, contingent on temperatures and cycling.

I think you have to perform the buried stress analysis simply as we do for a typical buried stress analysis.

See the attached image, we can assume that it is completely buried and there is throughout soil on left and right side of pipe.
So the earth weight due to soil prism on the same will remain the same even if we consider it typical buried case or your windrow case. For lateral soil stiffness, this assumption may be slightly conservative, but this may be ignorable.



What you have to care is the soil parameters like density etc while putting values in buried modeler. As i assume that it would be very low dense soil.

Regards,
Ali

I would not consider this type of piping as buried piping in the stress analysis. The thermal conditions are not given. In case the thermal load exist the side way restraining effect of the soil is not reliable or available. I guest this type of cover is used against the sun exposure by using the soil thermal conductivity.

The pipe will expand under the thermal load, the load will push the soil at around the elbows or turns with large radius, therefore the soil will not restrain the pipe at all.
Additionally the compaction cannot be guarantied since there is no sufficient side restraint of the soil. This will not provide the required axial restraint of the soil.
The top soil with this arrangement can be assumed as uniform load but this is not conservative at around the elbows/turns lateral and horizontal since the stay of the soil cannot be guarantied for the pipe uplift at elbows.

If I was the decision maker on the job and the pipe burial is too difficult and costly, I would provide bottom supports/guides for the pipe to be able to control pipe thermal/seismic behaviour, and still provide the soil cover similarly against sun radiation (if this is the concern) on the pipe steel if it is cheaper and safer than conventional hot insulation.

Hope it helps