WES Theoretical Manual, Part VIII: Penetration of the Inboard Sheeting (Plunging)

Plunging is the penetration of the inboard sheeting into the foundation. When the cell is loaded from one side, it tends to rotate, and the inboard wall carries more vertical load and can be driven downward into the ground, much as the outboard wall tends to pull up.

This part shows how the check is set up, how the vertical load on the inboard sheeting is found, and how that load is compared with the bearing capacity of the foundation under the sheeting tips. It follows the same free-body approach as the neighboring checks, so you can see how the pieces fit.

It is most relevant for cells on weak or compressible foundations, and it helps decide how deeply the sheeting should penetrate.