SLAB DESIGN CALCULATIONS
Project Name : Sample
Client Name : Sample
Engineer Name : Sample
Analysis File : D:\Bentley\Common data\Bentley Communities\ACI\ACI_M_Validation Sheets\STAAD file\RCDC-Staad-Demo -with RCC wall.std
Analysis Last Modified : 8/19/2020 6:09:29 PM
 
 
NOTES:
1. Density of concrete assumed as 25 kN/cum.
 
Definitions Of Terms: :
1. αf = Ratio of flexural stiffness of beam section to flexural stiffness of slab.
2. βt = Ratio of torsional stiffness of edge beam section to flexural stiffness of slab.
3. Φt = Strength reduction factor.
4. As = Area of Tension reinforcement required in 'sqmm'.
5. As,min = Min area of flexural reinforcement in 'sqmm'.
6. AstPrv = Area of longitudinal reinforcement provided at given section in 'sqmm'.
7. Ast = Total area of longitudinal reinforcement calculated at a given section in 'sqmm'.
8. b = Width of the Slab in 'mm'.
9. B1 to B4 = Width of beams around slab in 'mm'.
10. Cc = Effective Cover to tension reinforcement in 'mm'.
11. CA and CB = cross-sectional constant to define torsional properties of slab and beam.
12. deff = Effective depth of slab in 'mm'.
13. D1 to D4 = Depth of beams around slab.
14. Icr = Moment of Inertia of concrete crack section.
15. Ln = Length of clear span in direction that moment are being determined in 'mm'.
16. L2 = Length of adjacent span of Ln in 'mm'.
17. lb1 to lb2 = Moment of inertia of beams around slab in 'mm4'.
18. Mcr = Cracking Moment.
19. Mu = Factored Bending Moment at a section in 'kNm'.
20. Ptmin = Minimum percentage steel as per clause 10.
21. PtPrv = Provided percentage steel.
22. Vc = Nominal shear strength provided by concrete in 'kN'.
23. Vu = Factored Shear Force at a section in 'kN'.
24. Vud = Design Shear Force in 'kN'.
25. y = Neutral axis depth.

 
Code References :
ACI 318M - 2011
 
  Item   CLAUSE / TABLE
1. Ptmax : 10.3.5
2. Ptmin : 7.12.2.1/10.5.4
3. Vc : 11.11.2.1
4. Av : 11.4.7.2
5. Moment calculations : 13.6
6. spacing between main bars : 10.5.4
7. spacing between distribution bars : 7.12.2.2
8. Minimum reinforcement : 7.12.2.1
9. fs,perm : 10.6.4
10. fc,perm : 10.2.7.1
10. Wcr : Eq 4.2(a)

    
Slab No. : S6
Level = 7.858 m
Design Code = ACI 318M - 2011
Grade Of Concrete = C20
Grade Of Steel = Fy420
Clear Cover = 20.000 mm
Long Span, Ly = 8.900 m
Short Span, Lx = 8.000 m
Imposed Load = 5.000 kN/sqm
Live Load, Qk = 5.000 kN/sqm
Slab Thickness = 275.000 mm
Effective Depth Along LX, Deffx = 250.000 mm
Effective Depth Along LY, Deffy = 240.000 mm
Self Weight = 6.880 kN/sqm
Total Load, TL (ultimate) = 22.250 kN/sqm
Span = 2-Way
Load Combination = 1.2 DL + 1.6 LL
 
Short SpanLong Span
Side1Side2Side1Side2
Beam
        B (mm)450450450450
        D (mm)800800800800
        Ib (mm4)   x10619200192001920019200
Adjacent Slab
        Thk (mm)275275200275
        Span (mm)8000800057109050
        Ib (mm4)   x10613864.5813864.589615.5115554.33
αf lx, αf ly1.381.3821.23
αf1.5
Ln (mm)75508450
L2 (mm)46754225
Effective Width (mm)22252000
Ly/LxLx/Ly
1.110.9
Total BM (kNm)741.17839.04
Bottom
        Moment Co-efficent0.350.35
        Distributed Moment (kNm)259.41293.66
        Moment factor for CS0.7160.780
        CS Moment (kNm)185.8229.16
        MS Moment (kNm)73.6164.51
        Moment on Beam (kNm)157.93194.78
        Design Moment M1, M3 (kNm)73.6164.51
Top
        Moment Co-efficent0.650.65
        Distributed Moment (kNm)481.76545.37
        Moment factor for CS0.7160.780
        CS Moment (kNm)345.06425.57
        MS Moment (kNm)136.7119.8
        Moment on Beam (kNm)293.3361.74
        Design Moment M2, M4 (kNm)136.71119.8

Design Moments:
Short Span Positive Moment At Midspan -
M1 = 73.610 kNm
M1 (per m) = M1/Effective Width
= 33.080 kNm/m
Area Of Reinforcement Required (BM) = 356.350 sqmm/m
Reinforcement Provided = #10 @ 195 C/C
  = 363.000 sqmm/m
Short Span Negative Moment At Continuous Support -
M2 = 136.700 kNm
M2 (per m) = M2/Effective Width
= 61.440 kNm/m
Area Of Reinforcement Required (BM) = 672.480 sqmm/m
Reinforcement Provided = #10 @ 105 C/C
  = 675.000 sqmm/m
Long Span Positive Moment At Midspan -
M3 = 64.510 kNm
M3 (per m) = M3/Effective Width
= 32.250 kNm/m
Area Of Reinforcement Required (BM) = 362.280 sqmm/m
Reinforcement Provided = #10 @ 195 C/C
  = 363.000 sqmm/m
Long Span Negative Moment At Continuous Support -
M4 = 119.800 kNm
M4 (per m) = M4/Effective Width
= 59.900 kNm/m
Area Of Reinforcement Required (BM) = 684.370 sqmm/m
Reinforcement Provided = #10 @ 100 C/C
  = 709.000 sqmm/m
Distribution Reinforcement @ 0.18% -
Area Of Reinforcement Required = 450.000 sqmm/m
Reinforcement Provided = #10 @ 155 C/C
= 457.000 sqmm/m
Shear Check :
Along Short Span
Vsx (TL(ultimate) x Lx / 4) = 44.500 kN
Nominal Shear, ΦVc = 142.550 kN
  > 44.500 Slab Is Safe In Shear
Along Long Span
Vsy (TL(ultimate) x Lx / 2 x (1 - (Lx / (2 x Ly)))) = 49.000 kN
Nominal Shear, ΦVc = 136.850 kN
  > 49.000 Slab Is Safe In Shear