9.3.1.1

The cross-sections used for the columns and beams of the moment-resisting frames must not undergo local buckling and must be compact enough to provide certain ductility capacity.

Local buckling must be prevented for horizontal load-bearing system elements to perform sufficient plastic deformation under earthquake effects. For this purpose, the width-to-thickness ratios of elements must be satisfied according to the conditions given in Table 9.3.

Since the plastic deformation capacity of systems with high ductility level should be relatively higher, the limit values ​​are smaller.