Staircase Manual
Staircase Manual
Staircase Manual
)
Let thickness of waist slab be 150 mm 25 7
Yield strength of steel = 500 N/mm2
Dead load of flight
Step section = 0.02258 m2
inclined slab = 0.04651 m2
Finish = 0.0108 m2
Total area = 0.07988 m2
Density of concrete = 25 KN/m3
Dl of step section 1m in width= 1.997064422 KN/m
Dl per m2 on plan = 7.86246 KN/m2
LL per m2 on plan = 4 KN/m2
Total load = 11.8625 KN/m2
Factored load = 17.7937 KN/m2
width of slab = 1.52402 m
Total load /m = 27.12 KN/m
Load on landing
self weight of slab = 3.75 KN/m2
finish = 0.625 KN/m2
live load = 4 KN/m2
Total load = 8.375 KN/m2
Factored load = 12.563 KN/m2
width of slab = 1.52402 m
load = 19.145 KN/m
Now
Design of stair flight
Length of landing A= 1.46 m
Length of flight = 1.80 m
Length of landing B= 1.460 m
Reaction at support B = 52.33 KN
Reaction at support A = 52.32 KN
Let point of zero shear force occurs at x distance from A
x= 2.36 m
Maximum bending moments occurs at x = 2.36 m from A
Maximum bending moment = 66.95 KN-m
Therefore,
Effective depth of slab d = 128.511089
Adopt
d= 140 mm
D= 165 mm 6.496062992 in.
Now,
Area of tension steel (Ast) = 1334.81 mm2
Provide 12 mm dia bar @ 129.06 mm 5.08
Provide 12 dia bar @ 5.08 inch. c/c as 1722.8 mm2 OK
main bar
Temperature reinforcement
Provide 1-10 dia bar as temperature reinforcement in each riser.
In the waist slab provide 0.12 % steel = 198 mm2/m
i.e. provide 8 dia bar @ 253.74 mm c/c 9.99
Provide 8 dia bar @ 9.99 inch. c/c
in.
inch.
0.81
OK SAFE