For box systems, the gravity loads are transferred to the ground using a simply supported "post and beam" type system where the walls act as axial-loaded, (or combined axial plus bending), members. The following pictures will show the basic vertical load path from 1 to 2 to 3.
Box buildings make use of specially designed and carefully connected horizontal diaphragms and vertical shear walls to ensure lateral stability and the proper transfer of the lateral load to the ground. The basic lateral load path can be seen in the following pictures by moving from 1 to 2 to 3.
In rectangular buildings, lateral loads acting in the short direction (as
shown above) generally pose the greatest problem to the primary lateral force resisting
system, (LFRS). One must, however, always ensure lateral stability in both directions;
requiring a second set of calculations in the perpendicular direction.