STAIRCASE DESIGN
A3
MEHRO CONSULTANTS
STAIRCASE DESIGN
Fck (N/mm2)
STP
40
2
Fy (N/mm )
500
Depth of Waist Slab (mm)
225
Clear Cover (mm)
Waist Slab Bar Dia(mm)
Finishing Thickness(mm)
Landing Condition
Landing slab Bar Dia (mm)
Depth of Landing slab(mm)
Waist Slab Length(m)-----------( a )
Upper Landing Length(m)-------( b )
Lower Landing Length(m)-------( c )
Width of Landing slab(m)-------( w )
Height between two landing (m)
2
Dead Load (kN/m )--------------( 1 )
2
Live Load (kN/m )---------------( 2 )
2
Steps Load (kN/m )-------------( 3 )
2
Total Factored Load (kN/m )
22.88
(1.5*(1+2+3)/cos(θ))
Riser (mm)
Tread (mm)
Number of Steps
θ
Eff. Depth of Waist Slab (mm)
Eff. depth of landing slab (mm)
150
300
11
28.81
194
219
Section
Spanning of landing slab is allowed
Upper Landing allowed to
span
Lower Landing allowed to
span
30
Design of waist slab
12
75
Eff. Span (m)
Perpendicular Factored Moment (kNm)
12
Percentage of steel
2
250
Ast required (cm )
3
Spacing required (mm)
1.85
Spacing provided (mm)
2
1.65
Ast provided (cm )
4.1
Modification Factor
1.65
Actual (L/d)
7.31
Permissible(L/d)
4
Deflection Check
2.06
Total deflection(mm)
Revision
Made by: Zeeshan Qadri
R0
Date
Remarks
Current
st-01 5-5
Yes
0.75
(e)
Yes
0.75
(f)
4.75
62.52
0.42
8.09
140
100
11.30
1.34
16.61
26
OK
3.96
Shear force (kN)
43.08
Shear stress (N/mm2)
Ksτc
Check for Shear
Design of landing slab
Factored Moment (kNm)
Percentage of steel
Area of Steel (sq.cm)
Spacing required (mm)
Spacing provided (mm)
2
Ast provided (cm )
Modification Factor
Actual (L/d)
Permissible (L/d)
Deflection Check
Total deflection(mm)
Shear force (kN)-at distance
2d from support
Shear Stress (N/sq.mm)
Ksτc
Check for Shear
0.22
Check (TD<L/250)
O.K
At a distance 2d from
support
0.52
OK
Upper slab
112.23
0.69
13.44
84.14
80
14.13
1.01
19
20
OK
17.67
Lower slab
117.98
0.73
14.24
79.36
80
14.13
0.95
20
20
OK
18.74
86.10
90.51
0.39
0.54
OK
0.41
0.54
OK
Select Landing Condition as per figure shown
Print
IS: 456 Clause
33.1 Effective Span of Stairs
The effective span of stairs without stringer beams shall be taken as the
following horizontal distances:
a) Where supported at top and bottom risers by beams spanning parallel
with the risers, the distance centre-to-centre of beams;
b) Where spanning on to the edge of a landing slab, which spans parallel
with the risers ,a distance equal to the going of the stairs plus at each end
either half the width of the landing or one metre, whichever is smaller;
and
c) Where the landing slab spans in the same direction as the stairs, they
shall be considered as acting together to form a single slab and the span
determined as the distance centre-to-centre of the supporting beams or
walls, the going being measured horizontally.
IS: 456 Clause 23.2
The final deflection due to all loads including the effects of temperature,