Challenge

Foundation Design using SAFE

AIM:

MODEL THE ISOLATED FOOTING PROVIDED IN THE WEE 11 CHALLENGE ON SAFE. ANALYZE AND DESIGN IT TO VERIFY THE SIZE, DEPTH, AND STEEL PROVIDED AS PER CALCULATION.
A COLUMN OF SIZE 600X600 CARRYING AN UNFACTORED GRAVITY LOAD (DL+LL) OF 1175 KN IS TO BE SUPPORTED ON THE PILE CAP, WHICH ULTIMATELY TRANSFERS LOAD TO THE PILES UNDERNEATH. PILES OF 16 METERS IN LENGTH AND 500 MM IN DIAMETER ARE TO BE USED. EACH PILE HAS A LOAD-CARRYING CAPACITY OF 200KN. MODEL ANALYSIS AND DESIGN THE PILE CAP ON SAFE TO EVALUATE THE FOLLOWING

CHECK NEEDS TO BE DONE:
Safe bearing capacity under service load
Settlement under service load
Two-way shear check (punching shear)
Ultimate bending moment
Flexural reinforcement design for footing slab
GIVEN:
Square footing for a column size of 400x400
The compression axial load for the load combination of (1.5 DL + 1.5LL) is 2000 KN
The safe soil bearing capacity is 150kN/m²at a depth of 2 meters below E.G.L
Assume M25 concrete
SOLUTION:
Unfactored load = 2000/1.5 = 1333.3 kN
Dead load breakup = 1333.3/2 = 666.7 kN
Live load breakup = 1333.3/2 = 666.7 kN
Subgrade modulus for soil = safe bearing capacity x factor to ultimate/maximum settlement

= 150 x 3/0.05 = k = 9000kN/m^2

STEPS:
First, open the safe application and open the new model
Then click on unite as si and code as per Indian standard
After that open a single footing and enter the live and dead load as 666.7 and 666.7 simultaneously
After going for a defined material add the concrete M25
Then add rebar fe500 in material
After that add the slab section add footing, slab, and stiff
I have designed the footing of 800mm thick and 2400x2400
Then add the slab spring soil150 with a subgrade modulus of 9000kn/m^3

=196349 x 25000/16000

306796 kN/m

STEPS:
First, open the safe software and select the new model
Then select the unit as metric and code IS 456-2000
After that go for a design preference and choose 50mm each was provided as the cover top and bottom and the bar size was defined as 16mm
Coordinates were defined following grid spacing in the x direction and y direction was taken a and 1.65m
Its shown below figure too
After that, they check the safe
After that define the option and go for material property data and choose the concrete
M25-grade of concrete
Modulus of elasticity

E = √25 x 5000

= 25000 n/mm^2

And we next added rebar fe500 rebar was added next as shown below
Define slab properties and choose pile cap
Add to the slab properties add a column
Add defined pile details
Draw the slab by using the quick draw tool
To draw the points in the column
Add piles at the point and modify the edge distance to 0.3 m
Create a column of 600mm x 600mm draw the column in the center using the draw tool
Spring was added select pile to choose assign choose support data to choose point springs spring constant is taken frame above calculation
Dead and live loads of 587.5KN are added next
load case combination was defined next
after defining the load combination run the analysis displacement was to be .84 so it was safe
also, all the punching shear values are less than 1 so it's 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 directions respectively and run the analysis again
reinforcement slab design
pile cab foundation design