Foundation Design using SAFE
1.Given:
square footing for a column size of 400X400
compression axial load for the load combination of ( 1.5 DL + 1.5 LL ) is 2000Kn
the safe soil bearing capacity is 150KN/M^2 at a depth of 2 meters below EGL
Assume M25 concrete grade
Solution:
step 1)
required data
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 of soil = safe bearing capcity X factored to ultimate / maximum settlement
= 150 X 3 / 0.05 = k = 9000 KN/m^3
Rebar yeild strength ( Fy ) = 500N/mm^2
Rebar ultimate strength ( Fu ) = Say 575 N/mm^2
Elastic modulus of M25 Concrete = 2500 n/mm^2
Step 2)
safe design
open the safe software
click on the new model
in that choose single footing option
and press ok
after that fill all information like this \
and press ok
Step 3)
define material property
from define
then same for rebar
step 4)
Slab Properties
define slab properties from define
step 5) load cases
go to load cases from define
step 6) load combination
go to define
and click on the load combination
step 7) Run the analysis
step 8) draw design strip
step 9)
check
safe bearing capacity
from reaction
punching shear design
step 10)
strip forces
flexural reinforcement
Result: our sqaure isometric footing done successfully with all checkn
2.AIM: to deisgn a pile foundation usig safe software
Introduction: design pile footing by using safe software and do all required check, and try to design economic and safe structure, pile footing is done where hard strata available on depth
Data required
unfactored load = 1175KN
dead load breakup = 1175/2 = 587.5 KN
Live load breakup = 1175/2 = 587.2
Point spring of pile = A X E / L
= 196349 X 25000/ 16000 = 306796 KN
k for SAFE analysis = 306.8 KN/m
Rebar yeild strength (FY) = 500N/mm^2
rebar ultimate strength = 575 N/mm^2
Elastic modulus of M25 concrete = 25000N/mm^2
number of piles required = unfactored load with self weight addition / indivisual pile capacity
= 1175 X 1.1/200 = 6.5
consider 8 piles
take center to center distance between piles = 3 X piles diameter = (1500 mm)
Edge distance from pile center = 1 X pile dimeter = (500mm)
Assume pile cap depth = 500mm
step 2)
safe design
open new model
and put all required information
step 3)
material properties
click on material property from define
add M25 grade concrete material
and 500fy reabar material
step 4)
define slab property
step 5)
draw slab
draw the slab by using quick draw tool
step 6) draw refrence point:
draw refrence point
where we loacate the pile by the help of draw refrence point and replicate option from edit
like that
step 7) add the pile
add the piles at the point
draw the pile by using quick draw area around pint
set dia as 500mm
and draw by cursor
like that
step 8) same draw column
by choosing rectangular slab
step 9) assign a spring
selcect all the pile point
now go to draw
then support data and point spring
step 10) add load
assign load to column
simply select the column point
go to assign
go to joint load
and then select garvity dead and live load are 587.5 kn
step 11) check design preference
check design prefrence before analysis from design option
step 12) run the analysis
step 13) check for rection
check base rection for unfactored load
when we design for steel we need to check for factored load
step 14) check for punching shear design
from disply option
step 15) design strip
to know the area of steel required
go to edit option
and click on add design strip
same do for Y direction and strip layer B
so strip is assign for X and Y direction
check width of strip
from display option
step 16) define load combination
from define option
step 16) again run the analysis
and check the r/f required
go to display option then slab design
and strip A press apply
and for strip B for y direction steel
Result: design of pile foundation is done successfully with given data
and also done all check satisfy
and get quantity of steel required