Foundation Design using SAFE
question 1
Aim:
To Analyze and designthe isolated footing from week 11 challenge on SAFE
To verify the size, depth and steel provided as per calculations.
Procedure:
Create new model then go to input the metric units byusing code usage IS 456-2000
Step:1
Open the SAFE Application
select New Model
followed by Input Settings,
Units was selected as Metric and Code IS 456-2000.
Step:2
In the window for default, Select single footing,
Input the required dimensions and loadings in the respective locations.
Subgrade modulus of the soil=FOS x SBC / settlement of soil
Where SBC=150kN/m2
Factor of safety (for footing)=3
Considered settlement of the soil =50mm
Subgrade modulus=9000kN/sq.m
For load combination of 1.5(DL+LL), the resultant compression axial load =2000kN
Unfactored compression axial load =1333kN
Dividing to DL & LL =1333/2
=666.65kN
For column size the provided square footing is 400x400
The assumed concrete footing thickness in 0.8m
Step:3 Material definition:
Defining material property, Concrete M25.
Modulus of elasticity =E=25000 N/mm2
Defining rebar details:
Reinforcement material added for HYSD 500 and the respective material properties are all inputed.
Step 4 SECTION PROPERTIES
Defining the section properties of the model.
Define> Slab porperties
For footing the slab is considered as Mat type property and considered thickness of 300mm thick.
Defining the stiffened member using same as the slab property definition- slab stiff options as given below,
For footing, the slab thickness is assigned as 800mm thick and the slab type is considered as Footing,
Step-5 -Load Assignments:
Defining the load patterns for dead and live load I,
Define goto load pattern and set Dead & Live load added.
Select the point of column resting location, assigning the dead and live load
After the load assignments assign the load combinations,
For ultimate and service load combinations.
STEP: 6
Assign point load
STEP: 7
Assign load combinamtions
STEP: 8
check design preference (min cover 50mm)
STEP: 9
run analysis and design
QUESTION: 2
:
AIM:
- TO MODEL ANALYSI, AND DESIGN THE PILE CAP ON SAFE
- TO EVALUATE THE FOLLOWING:
- Pile group to be used
- Depth of pile cap
- Longitudinal steel on top and bottom face in both directions
PROCEDURE:
GIVEN DATA:
STEP: 1
Open the SAFE Application
select New Model
followed by Input Settings,
Units was selected as Metric and Code IS 456-2000.
50mm each was provided as cover at top and bottom and Bar size was defined as 16mm
STEP: 2
Coordinates was defined next.
Grid spacing in X direction and Y direction was taken as 2.9m and 1.65m
respectively.
It's shown in the below figure too.
STEP: 3
Material Property data:
- Click define followed by Material properties
- M25 grade of concrete
- Modulus of elasticity,
E = √25 X 5000
= 25000N/mm²
- Fe 500 Rebar was added next as shown below
STEP: 4
Define slab properties
- define pile cap
- define column
- define pile details
STEP: 5
Draw the slab by using quick draw tool
draw points
STEP: 6
Add piles at the point
modify the edge distance to 0.3m
STEP: 7
Create a column of 600mm x 600m
draw the column in center using quick draw tool
STEP: 8
Springs were added
select pile< assign < support data < point springs
Springs constant is taken frome above calculation
Dead and Live Load of 587.5KN are added next
STEP: 9
Load case combination was defined next.
After defining the load combination run the analysis
max displacment was found to be .84
so its safe
Also, all the Punching shear values are less than 1
so its safe.
joint reaction diagram
as all the reaction forces are according to the limit,
its safe
Reinforcement details are added next as shown in both X and Y direction respectively and run the analysis again
STEP: 10
Reinforcement slab design:
pile cap foundation design