1

2

DESIGN OF SLAB USING SAFE

3

SLAB DESIGN USING SAFE SOFTWARE

DATA FOR SLAB DESIGN

NO. OF SLAB PANELS (X- DIRECTION) = 2

NO. OF SLAB PANELS (Y- DIRECTION) = 3

X-DIRECTION SPACING = 24’

Y-DIRECTION SPACING = 18’

SLAB THICKNESSTAKEN = 6 INCH

fc’ (28 DAYS COMPRESSIVE STRENGTH) = 3000 psi

fy (YIELD STRENTH OF STEEL ) = 60,000 psi

4

STEP 01 Grid Definition

File – New – Grid Definition .

No of Grid Lines (x-direction) = 3

No of Grid Lines (y-direction) = 4

Grid Spacing (x-direction) =24’

Grid Spacing (y-direction) =18’

For editing in Grid Spacing, use command Edit – Edit Grid .

Units = Kip-ft

5

6

7

STEP 02 PROPERTIES DEFINITION

For defining the properties of different elements, use following Command,

Define – Slab Properties – Add new property – Set property name as Slab1In type click Slab, thickness = 0.5’ , give cover = 0.08’ ( 1 inch),Give fc’ and fy and Modulus of elasticity accordingly.

After this use following command & procedure

Define – Beam Properties – Add Rectangular Beam-Set Beam property name as Beam1.Give depth = 2’ & width = 1’ , give cover = 0.16’ ( 2 inch),Give fc’ and fy and Modulus of elasticity accordingly.

8

STEP 02 PROPERTIES DEFINITION

Then use following command to define column properties

Define – Column Supports – Add New Property-Set property name as Col1.Give column dimensions = 1’ (X-dimension) , 1’ (Y-dimension) Column Height = 10’,Give fc’ and fy and Modulus of elasticity accordingly.

To draw beams in model useDraw – Line Objects.

To draw slab in model useDraw – Draw area objects.

To draw column in model useDraw – Draw point objects

9

STEP 03 ASSIGNING PROPERTIES

After defining all properties, these are assigned to relative elements

slab, Beam & column as shown in next slides.

To assign slab properties in model use

Assign – Slab properties.

To assign beams in model use

Assign – Beam properties.

Assigning Slab.

11

Assigning Beams.

12

Assigning Column Supports

13

Step 04 Load Application

Load cases are defined using following command

Define – Static Load Cases –

Load 1 – DL Selfwt multiplier =1 & Long term deflection factor =3

Load 2 – LL Selfwt multiplier =0 & Long term deflection factor =1

After selecting the slab, load is applied using following command

Select slab – Assign – Surface loads – DL – Load per area = 0.05 (ksf)

Select slab – Assign – Surface loads – LL – Load per area = 0.06 (ksf)

14

Assigning Load

15

Step 05 Defining Load Combination.

Load combinations are defined using command

Define – Load Combinations

Comb 1 - 1.2 DL + 1.6 LL

16

To view the properties of element ,rendered view, or mesh of slab use following command

View – Set object options – Area object properties or show mesh.

To display the applied load

Display – Show Loads.

Auto Mesh of Slab.

18

Step 06 Analysis of Model.

Analysis can be performed using command

Analyze – Run Analysis.

Step 07 Analysis Results .

Deformed shape can checked using command

Display – Show Deformed Shape. Max Deflections must be with in permissible limits .Max Deflection due to loads for this case is 0.23 inches.

Slab forces can be obtained using command

Display – Show Slab Forces.

19

Step 07 Analysis Results .

To obtain the results of beams

Display – Show Beam Forces.

To obtain the results of slab strips

Display – Show Strip Forces.( Moments & Shears)

To obtain the results in tabulated form

Display – Show output tables.

Deformed Shape of Slab.

27

Step 08 Design of Slab & Beams

To design the slab, use following command

Design – Select design combinations

Then Start Design

To check the results of reinforcement

Design – Display slab design info – Show rebar area.

Then click on X-strip reinforcement to check x-direction reinforcement.

Then click on Y-strip reinforcement to check Y-direction reinforcement.

28

Step 08 Design of Slab & Beams

To check the results of punching shear

Design – Display punching shear ratios .(It must be less than 1.)