If φ is the diameter of a plain bar in compression, σst is the design stress in the bar, and τbd is the design bond strength of concrete, determine the basic development length (Ld) of the bar as per IS 456:2000.

For axial load and combined biaxial bending moment in the iteration formula used by IS 456, αn is based on Pu / Puz, where Puz is given by:

A compression member is considered to be short if its slenderness ratio satisfies which of the following conditions?