The overall foundation stability may be assessed using a phased method with three steps increasing in order of complexity:

• Step 1: Preload and Sliding Check.

The foundation capacity check is based on the preloading capability. Sliding of the windward leg is also checked. Loads from pinned footing analysis.

• Step 2: Bearing Capacity Check.

•  Step 2a: Bearing capacity check, based on resultant loading, assuming a pinned footing. Also check sliding.

•  Step 2b: Bearing capacity check, including rotational, vertical and translational foundation stiffness.

• Step 3: Displacement Check. The displacement check requires the calculation of the displacements associated with an overload situation arising from Step 2b.

Any higher level check need only be performed if the lower level check fails to meet the foundation acceptance criteria given in the latest version of SNAME standard.