Minimal Pipe Cover during Construction - Floating of Pipe

[Thurston]

I'm working on a project where we are installing an 8' diamater drainage pipe in an area that has a after-rain high water table.

Is there a rule of thumb on how much cover should be placed on the pipe to keep it from floating out of the ground? The concern is that it will be empty and the bouyance of the saturated soil around it will cause it to float.

Thanks in advance.

 

[RWF7437]

For a pipe this large it may be necessary to install concrete anchors to prevent flotation. For an 8 foot pipe you can calculate the bouyant force if the water table is at the top of the pipe as 0.785D^2*(62.4 lb/ft)= 3135 lb/ft of length, roughly. You'll probably want to add a safety factor of 1.5 to any calculation you do just to be sure.