WES Theoretical Manual, Part VII: Pullout of Outboard Sheeting

This part covers pullout of the outboard sheeting. The lateral forces on the cell make it rotate about the toe, which tends to pull the outboard sheeting and the crosswall up out of the foundation, while the berm material pushes back.

The manual gives the factor of safety as the maximum available resisting moment divided by the driving moment, where the resisting moment comes from the ultimate pullout capacity of the outboard sheeting and half the capacity of the common wall. It shows the portion of the cofferdam isolated as a free body, the vertical distances used to find the driving moment, and the external forces and effective soil pressures acting on the walls.

The check matters mainly for cells embedded in soil, where the pullout resistance depends on how deeply the sheeting is driven.