Slab design calculation one way and two way method in excel sheet with example

Engr. BalaramEngr. Balaram July 19, 2021


Civil or structural engineer know that how to calculated slab design. Here you can get a free excel sheet where a engineer easily design one way or two way slab by one click. We also explain a slab design example in this excel sheet. 

Download this Excel Sheet: Slab design calculation excel sheet
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Slab design calculation one way and two way method:

An Example of two way design calculation:

Input data:


Slab Dimensions:

Short span = 10 ft.
Long Span = 15 ft.
Span ratio = 10/15 = 0.67
Slab thickness (reqd) = 2 x (10+15) x 12/180 = 3.33 in
Slab thickness (prvd) = 5 in.


Edge Conditions:


Short span edge condition = Both edges continuous
Long span edge condition = Both edges discontinuous



Applied Loads: 


Slab self wt = 62.50 psf.
Service dead load = 40 psf.
Service live load = 75 psf.
Material Strengths:
Concrete Strength = 2.5 ksi.
Steel yield strength = 60 ksi.


Design Moments


Loads:

Total ultimate DL = 1.4x(62.5+40) = 143.5 psf.
Total ultimate LL = 1.7x(75) = 127.5 psf.
Total ultimate load = 143.5+ 127.5 = 271 psf.


Short Span Moments:

Positive Moment DL Muall(dl)+ = 0.036 x 143.5 x 10^2 = 0.517 k-ft.
Positive Moment LL Muall+ = 0.054 x 127.5 x 10^2 = 0.689 k-ft.
Total positive short span moment mua+ = 1.205 k-ft.
Negative Moment on Discontinuous Edge = 1/3 x 0.416 = 0.139 k-ft.
Negative Moment on Discontinuous Edge = 1/3 x 0.416 = 0.139 k-ft.

Reinforcement Calculations




Shear Check:
Total load on the panel = 10 x 15 x 288.5 = 43.2 kips
Shear Capacity of the section fVc = 0.85 x 2 x ( 2500 )^½ x 12 x 5 / 1000 
    = 5.1 k/ft
Shear along short side      Vua  =  ( 0.04 x 43.2 ) / (2 x 10 ) 
= 0.08 k/ft    <5.1 k/ft…. (O.K.)
Shear along short side      Vub =( 0.04 x 43.2 ) / (2 x 10 )
 = 0.08 k/ft <5.1 k/ft…. (O.K.)
Short Span Moments:
Positive Moment DL Mua(dl)+ = 0.036 x 161 x 10^2  = 0.580 k-ft
Positive Moment LL Muall+ = 0.054 x 127.5 x 10^2 = 0.689 k-ft
Total Postive Short Span Moment Mua+ =  1.268 k-ft
Negative Moment on Continuous Edge = 0.087 x 288.5 x 10^2  = 2.510  k-ft
0.087 x 1.268
0.087 x 288.5 x 10^2
Negative Moment on Continuous Edge = 0.087 x 288.5 x 10^2 = 2.510 k-ft
0.087 x 1.268
0.087 x 288.5 x 10^2
Long Span Moments:
Positive Moment DL Mubdl+ = 0.004 x 161 x 15^2  = 0.145 k-ft
Positive Moment LL Mubll+ = 0.01 x 127.5 x 15^2  = 0.287 k-ft
Total Postive Long Span Moment Mub+  = 0.432  k-ft
Negative Moment on Discontinuous Edge = 1/3 x 0.432 = 0.144 k-ft
1/3 x 0.432
1/3 x 288.5 x 15^2
Negative Moment on Discontinuous Edge = 1/3 x 0.432 = 0.144 k-ft
1/3 x 0.432
1/3 x 288.5 x 15^2

If you insert One way slab data. then this calculation result show for one way slab. 

You can also downloads  

One way slab design example pdf

Two way slab design example pdf


For any problem in this design calculation excel sheet, comment blew, thank you.
Engr. Balaram

Posted by Engr. Balaram

BalaRam is a Civil Engineer who has more than four years of experience in Structural and Civil Engineering. He is the author, editor and partner of www.CivilSite.info.

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5 Comments

  1. UnknownAugust 10, 2021 at 5:43 AM

    Slab design excel sheet protected with password, Please tell the Password
    Thanks.

    ReplyDelete
    Replies
    1. Engr. BalaramAugust 12, 2021 at 8:03 AM

      Password is not important.. It's work without password.

      Delete