Design Of Staircase.xls

Design of Staircase Y= Effective Span Riser (R) Tread (T) √ (R2+T2) Assume waist slab thickness (d) Overall Depth (D) Assumed grade of concrete (fck) Assumed steel (fy)

25

4.09 178 254 310.16 125 150 M20 Fe 415

Loads on stairs Self weight of waist slab Self weight of steps Finish Live Load Total Load

KN/m3 m mm mm mm mm mm

4.58 KN/m2 2.225 KN/ m2 1.1 KN/m2 3 KN/m2 10.90 KN/m2

Loads on landing Self weight of slab Finish Live Load Total Load

3.75 KN/m2 1.1 KN/m2 3 KN/m2 7.850 KN/m2

Design Moment considering 1 m wide strip fo waist slab. Reactions RA = RB =

18.68 KN 18.87 KN

Max moment at x=

2.055

m from A support

BMmax

20.76

KNm/m

Depth required M=2.76bd^2 (for M20 and Fe415) d d (provided)

86.73 125

mm mm (OK)

501.79 12 225.48

mm2 mm mm

Ast required BM= 0.87fy Ast (d-(Ast*fy)/(fck*b))

Ast φ= spacing required Distributors

= 0.12% of b D φ= spacing Shear check Max shear at distance d from the support Vu = Τv = Vu/b d

180 8 279.37

mm2 mm mm

18.38 KN 0.147 N/mm2

Τc % = 100 * (Ast/b d) Τc = k= k Τc =

Provide 12 mm φ @ 150 mm spacing c/c Provide 8 mm φ @ 150 mm spacing c/c

0.40 % 4.33E-01 for M 20 1.3 5.62E-01 N/mm2 > Τv (OK)

Main bars Distribution bars

c/c distance between two supports = Riser 7 inch Tread 10 inch A B Distance

Ra+Rb= ∑ Ma = 0

4.01 5.83 3.58 f 1.223 1.777 1.091 m Floor lvl steps first landing

37.55

Rb =

18.87 KN

10.30201 SF1

Ra =

18.68 KN

9.082896 SF2 2.055

x=

BMmax =

20.76 KNm/m

13.42 4.090416

0.15

0.28

0.25 0.25

0.36 0.36

0.5 4.01E-01

0.48 4.33E-01