As.provided = 4 x π x (20/2)^2 = 1256 mm^2

VEd = 1.35 x (10 x 6 / 2) + 1.5 x (5 x 6 / 2) = 54.5 kN

The critical buckling load is:

The required reinforcement area is calculated as:

The column is checked for buckling:

The slab requires additional shear reinforcement.

The beam is checked for shear resistance:

The column is stable.