A = Gross floor area
A b = Total void areas

A2 - Floor Discontinuities: In any floor slab (Figure 3.2) ;

I - Including stairs and elevator shafts, the total of void areas exceeding 1/3 of the floor gross area,
II - The presence of local floor gaps that make it difficult to safely transfer earthquake loads to vertical bearing system elements,
III - Sudden decreases in the in-plane rigidity and strength of the floor in case of

TBDY Article - In buildings with A2 and A3 type irregularities, floor slabs will be modeled with two-dimensional plate (membrane) or shell finite elements to show that they can safely transfer earthquake forces between vertical bearing system elements in their own planes (See ).

According to Article - of TBDY , in buildings where there are A2 and A3 type irregularities and / or floors are not intended to operate as a rigid diaphragm , and in slab systems without reinforced concrete beams, floors will be modeled with two-dimensional finite elements.