We know from experience that 3D Analysis on its own does not give the gravity results engineers have traditionally used or want - staged construction analysis reduces but doesn't resolve this. Therefore, Design All (Static) will also automatically undertake a grillage chasedown analysis provided concrete members exist anywhere in the model (beams, columns, or walls).
The Solver Model used for Grillage Chasedown emulates a traditional analysis and establishes an alternative second set of design forces for beams, columns and walls.