Staircase design using eurocode 2
Waist = 150 mm
Rise = 150 mm
Treads = 250 mm
Finishes = 1 kN/mm2
Span = 3.3 m
Live Load = 4 kN/mm2
Cover = 25 mm
Concrete = 25 N/mm2
Load Calculation
Total Dead Load = 5.625 kN/m2
Variable load = 4 kN/m2
Ultimate load = 1.25*5.625 + 1.5*4
= 13.03 kN/m2
Moment = W*l2/8
= 13.03*(3.32)/8
= 17.74 kNm
d = 150-25-12/2
= 119 mm
k = M / (b*d2*fck)
= 17.74*106/ (1000*1192*25)
= 0.05
z = (d/2)[1+(1-3.53k)0.5] ≤ 0.95d
= (d/2)[1+(1-3.53*0.05)0.5] ≤ 0.95d
= 0.954d ≥ 0.95d
Hence
z = 0.95d
= 0.95*119
= 113.05
As = M/ (fyd* z)
= 17.74*106 / (500*113.05)
= 313.84 mm2
Proved T10 @ 150mm c/c