HelicalStairs Reinforcement

Section considered for Design Case

Breadth

Depth

Main Steel

b

h

Edge Steel

h

b

Lateral Shear

b

h

Radial Shear

h

b Main steel

Closed links

provided for Shear

and Torsion

b

Vh

h

Radial Horizontal Shear

Mv Vertical Moment

Mn

T

Torsion

N Thrust (Tension/Compn.)

Edge steel provided for Mn + equivalent moment due to Torsion

Lateral Moment

Vn

Lateral Shear

STRESS RESULTANTS IN WAIST SLAB

provided for Mv + equivalent Moment

due to Torsion + Thrust

Waist = h Width = b

+ Thrust

REINFORCEMENT IN WAIST SLAB (TYP)

R.C. HELICAL STAIRS