Foundation Design using SAFE
A. open a new model , as per IS code 456
Unfactored load = 2000/1.5=1333.3 KN
dead load = 1333.3/2=666.7 KN
live load = 1333.3/2=666.7 KN
subgrade modulus for soil= safe bearing capacity x factor of safety / maximum settlement
= 150x3/0.05= k= 9000 kN/m3
column size of square footing 400x400
Assume concrete thickness footing as 800mm
Rebar yeild strength (Fy)= 500 N/mm2
Rebar ultimate strength(Fu)= 545 N/mm2
Elastic modulus of M25 grade concrete= 25000 N/mm2
Go to define , material properties
Go to define, section properties
Go to define, load patterns
Go to define, load combination
Go to draw , draw design strips
Run analysis results
since deflection is 3 mm is allowable
punching shear design values is also ok
deformed shape foe SLS
deformed shape for ULS
slab design
strip forces
2. column size of 600x600mm
Axial load (unfactored load)= 1175 KN
pile length= 16m
diameter of pile= 500mm
load capacity of each pile =200KN
unfactored load = 1175 KN
dead load = 1175/2=587.5 KN
live load = 1175/2=587.5 KN
calculation of no of piles = axial load / load capacity of pile
1175/200= 5.8
assuming 6 no of piles
spring constant = EA/L
Elasticity modulus (E)=25000 N/m2
Area of pile (A)= 3.14x(500)2/4= 196349 m2
Length of pile= 16000 mm
minimum spacing between piles= 3x dia of pile
3x500=1500mm
edge distance from pile center = 1x pile dia =500mm
Assumed pile cap depth =500mm
Open a new model as per IS 456-200
custom grid data
Go to define, material properties
Go to define, section properties
Adding a pile cap of 800mm thick to model using quick floor area toolbar
go to draw points , assign points width spacing aa 1.5m between pile points
Using quick floor area toolbar assign pile-500mm to points and column stiffner to column at center
go to assign , spring for pile support loaction
spring constant = EA/L
(25000x196349)/16000= 306795 N/mm
DL+LL=587.5 KN are added to column
Go to definre , load patterns
Go to define , load combinations
Draw strips to model in x, y directions
run analysis results
punching shear value
slab design
Strip A
strip B
design check
