Bouyancy Effect for Subsea Piping (Embedded in Sea Bed)

Hello fellow Stressers!!

I'm a bit confused by this statement which I found on some technical article:

"Soil stiffnesses calculated on embedded or semi-embedded pipe should take account of the buoyancy effect
of the water, e.g unit weight of the soil 114 pcf - weight of the seawater (64 pcf) = 50 pcf"

My question is why we need to get the difference in soil unit weight to sea water unit weight for the buoyancy effect. If the pipe is embedded then I think there will be no buoyancy effect since it will be isolated by the soil?

Please correct my interpretation of the topic in case I'm wrong.

Appreciate your opinion on the subject.

Thanks in Advance,

Water permeates the ground and the fluid with solids will act just like fluid if you give it a large enough time scale.

This happens in Louisiana, without a body of water sitting on top of it.

Thanks Michael for the response. Therefore the net buoyancy force is the solid (soil) minus the fluid (water) density and it happens in a long span of time. In this case, there will be two extreme cases, one without the buoyancy effect (newly installed pipeline) and with the net buoyancy effect (after a long period of time) where the water sips in the soil.


Please correct if my statement is interpreted right.

Cheers!!!

I can't correct you if you interpreted my statement correctly.

Though I'll clarify my second statement: it should have stated "this happens in some places in Louisiana, even in cases where there isn't a body of water above the pipe."

Thanks Michael for the response. You always find time to answer my doubts.

More power to you and all stressers!!!

Cheers!!!