DESIGN OF FOUNDATION
COLUMN (SQUARE)
DATA:
Load on the Column (P)         =          300 KN
DESIGN CONSTANT:
FCK                                    =          20 N/mm2
FY                                =          415 N/mm2
P            =        300 103 N
PU          =        300 103 1.5
PU          =        450 KN
TO GET AG:
Minimum % of steel to be provide in a R.C. Column = 0.8%
Assume 1% of longitudinal steel in the column
Area of  steel Reinforcement( ASC) = 0.01 Ag
Area of Concrete( AC) = Ag – 0.01 Ag
AC = 0.99 Ag
PU = 0.4 fck AC + 0.67 fy ASC
450 103 = 0.4 20 0.99 Ag + 0.67 415 0.01 Ag
10.70 Ag = 450 103
Ag = 42056.07 mm2
Size of the Column     = =     205. 07 mm = 300 mm
Size of the Column     =          300mm 300mm

LONGITUDINAL REINFORCEMENT:
Area of Steel Required           =         0.01 Gross Area
=   0.01 42056. 07
=   420. 56 mm2
Provide 10 nos of 16 mm bars
Nominal Cover = 40mm
Asc =  452. 38 mm2
DESIGN OF LATERAL TIES:
Minimum diameter laternal is the greater of
1.           ¼ dia of longitudinal bars
¼ 12 = 3 mm
2.           6 mm
Hence adopt 6mm dia lateral ties
PITCH:
1.                       The least lateral  dimension of column         =          300 mm
2.                       16  times of longitudinal bars                    =          16 16   = 256mm
3.                       300 mm
Provide  6mm lateral ties @ 250 mm c/c  