The design of a cofferdam requires providing an adequate margin of
safety against the following:
1. Cell sliding (Fig. 15-5a)
2. Cell overturning (Fig. 15-5b)
3. Cell bursting of Fig 15-5c, which is usually critical since the interlock
(thumb and finger joints) are the weakest part of the system.
4. Cell shear along the centerline and including a component of
interlock friction as illustrated in Fig. 15-5d.
5. Bearing capacity and settlement (not shown)