Foundation Design using SAFE

• Model the isolated footinf provided in week 11 challenge on SAFE. Analyze and design it to verify the size,depth and steel provided as per calculations

• PROCEDURE

1. Open the SAFE 2020 Software
2. CLick on the new model
3. CLick on the new model
4. Display Units - Metric SI
5. Dlect the Region -Indian
6. Select the Concrete Design Code -IS 456:200
7. Click on Okay

• STEP 2)
• Now following box will open
• Select the Single Footing

• STEP 4)

1. Enter the dimension as per calculation we done in week 11 challenge
2. Footing Size - 4 X 4 M
3. Footing Slab thickness = 800mm
4. Now Modoulous Subgrade = FOS x SBC /AllowableSettlement

FOS =3 as per IS 13920 SBC = 150 Given Allowable Settlement =0.025 as per 1904

Modoulous Subgrade = 3 X 150/0.025

= 9000 Kn/m^3

Now add the load

For dead load and live load = Total unfactored load /2

= 1333.3/2

=666.7 Kn

Column SIze = 400 X400

Now enter all the details click on the okay

STEP 5)

1. Once you click okay
2. Now geometry is created in mmodel space as follows

STEP 6)

1. Click on Define ---> materials Properties
2. new materials
3. Material type - Concrete
4. Grade 25

• Click on the Material -rebar Properties
• Grade -Fy 500

• Property Has been define

STEP 7)

• Now we have to define slab properties

• Property - Footing
• Slab material - M25
• Assign thickness - 800mm

• Modify stiff slab
• Slab material - M25

STEP 6)

• Assign soil properties
• Define - Soil Properties

• Right Click on slab and you will see sign properties has been assigned

• Now add load Dead live - 666.7 Kn
• Live Load -666.7 Kn

• Now Define the load Combination
• Define - Load Combination ---> Add new combo

• Now Check the model
• Then run the model
• Save the file
• Now see the displacement

• Displacement is less than 25 mm so its SAFE

• 

• Bearing Pressure is less than 150 KN/m so its SAFE

• Click on the Punching pressure
• As Punching shear is less than 1 so its SAFE

• Now add Design strips
• Click on Edit -Add/Edit design strips
• Add strips in both X and y direction

• Strip has assigned

1. Now again run model
2. Click on slab Design
3. Select the layer A

• Select the layer B

• RESULTS

1. Isolated Footing is designed for square column sizew 400 X400
2. We have to provide footing size as 4m X 4m
3. BEaring soil pressure is checked and it is safe
4. Punching shear ratio is check and found to be safe

Q2)

AIM: To model analyze and design the pile cap on SAFE

PROCEDURE:

Step1) : Given data

Column Size : 600 X 600

Unfactored Load : 1175 KN

Pile length : 16m

Pile diameter : 500mm

Load carrying capacity : 200 KN

• Calculation

Number of Piles : 1175/200 = 6

Spring Constant : E X A /L

: 25000 X 196349/16000 = 306749 N/m

• As per Is 2911 the spacing between the pile is takewn as 2.5 times the diameter of pile
• Edge spacing 300mm

• STEP 2)

1. Open the SAFE SOPFTWARE
2. Click on the new model

• Click on grid only
• No of grids in X and Y = 2
• Enter Spaciong in X =3.1 m
• Enter spacing in Y = 1.85m

• Assoign Material
• Define -Material Properties
• CLick on add material

• Click opn add new material add then following parameter
• Material type - COncrete
• Grade -M25

• Similarly add rebar material

• Properties has been define

• Step 6)

• Now we have to define slab preperties
• Pile cap we have to define 3 slabs properties
• Footing
• For COlumn
• FOr Pile Cap

• Now start modelling
• Select quick draw option
• Select footing and draw slab
• Similarly draw pile caps and column

• Now add springs to the pile caps
• Assign - data spring -point springs
• And then add lpoad combination
• Define - Load combination
• Define -load combination as follows

• Now run the model
• Click on the run analysis
• Check fopr the punchuing shear 0.49<1

• Check for the joint reaction

• Now add design strip
• CLick on edit -add design strip
• Add strip in bopth x and y direction

• RESULT

1. Pile cap is designed for square column of size is 600 X 600
2. WE have to provide pile cap size as 3.1X1.85m
3. bearing soil pressure is checked