WES Theoretical Manual, Part II: Analysis of Failure Modes

Over the years, a long list of failure modes has built up, and this part sorts them out. It describes how a cell can fail, which of the modes are well supported by model tests and field experience, and which rest on weaker evidence.

It sets up the free bodies used in later parts, including the equivalent cofferdam, the forces from water and soil outside the cell, and the pressure of the fill inside. It also explains why designers often analyze one wall, or the pair of inboard and outboard walls together, and what each choice assumes. For example, a single-wall free body that treats the wall as flat leaves out the horizontal component of interlock tension, which is actually the main way the wall resists the fill.

The result is a clear map of the checks in the parts that follow, so you know what each one is for before you start calculating.