Column designName of work:- pkn

1 External + self load 1200 kN Height of column 6.00 mtr

2 Concrete M- 25 Grade Unit weight concrete 25000

6 m 13.33

3 Steel fy 415 Tensile stress 190

4 Nominal cover 40 mm Effective cover 50 mm

5 Reinforcement Main vertical 20 6 Nos bars

6 2 - lgd. Strirrups 6 280 mm c/c

7 Rectangular Coloumn Size width 495 mtr depth 330 mtr

6 Nos. 20

495330

6280 m c/c

495

330

6.00

Ractangular column

Foundation pad

N/m3

cbc N/mm2

N/mm2 N/mm2

mm

mm

mm bars

mm 2 ldg strirrup

pk_nandwana@yahoo.co.in

Column design

1 External + self load 1200 kN/m Height of column 6.00 mtr = 60002 Concrete M 25 Unit weight concrete = ###

6 m = 13.333 Steel fy 415 Tensile stess = 1904 Nominal cover 40 mm Effective cover = 50 mm

1 Design Constants:- For HYSD Bars Cocrete M = 25

190 wt. of concrete = 25000 6

m 13.33m*c

=13.33 x 6

= 0.29613.33 x 6 + 190 1 - 0.296 / 3 = 0.901 0.5 x 6 x 0.90 x 0.296 = 0.8010

2 Design of section:-Minimum steel = 0.80% Let us use = 1 %steel 0.01Design column as a short columns

=p

=1200 x 1000

=152091

6 x( 1 - 0.01 )+ 0.01 x 190

Size of square column = ( 152091 = 390 mm Provide = 390 x 390Area of columns = 390 x 390 = 152100

3 Check column whatever short or long.= Height of column x Effective height factor

Here, = 6000 x 1 = 6000 mm b = 390 mm

Hence Hef = 6000 = 15.38 > 12 Design as long columnb 390

Reduction factore = Cr = 1.25 - Hef = 1.25 - 6000 0.9348 b 48 x 390= 1200 x 1000 = 1290323 N

0.93

=p

=1290323

=163539

6 x( 1 - 0.01 )+ 0.01 x 190Revised Ractangular column 1.50 x2= 163539 = 109026 x = 330 say 330

Size = 330 x 495 Area = 163350 (b = 1.5 d Assume)

N/m3cbc N/mm2

N/mm2 N/mm2

st = N/mm2 N/mm2cbc = N/mm3

k= m*c+stj=1-k/3

R=1/2xc x j x k

The load carring capacity of short column is p = cbc . Ac +st. Asc =cbc(Ag - pAs)+ st.pAs

From which Ag cbc (1-p) +p.st mm2

)0.5

mm2

Effective hieght of column Hef Hef

Revised Load P1The load carring capacity of short column is p = cbc . Ac +st. Asc = cbc(Ag - pAs)+ st.pAs

Revised Ag cbc (1-p) +p.st mm2

or x2

mm2

4 Longitudinal Reinforcement:-0.01 x 163539 = 1635

using ### mm bars A = = 3.14 x 20 x 20 = 3144 x100 4 x 100Nomber of Bars = = 1635 / 314 = 5.21 say = 6 No.Hence Provided 6 bars of 20

having, Ast = 6 x 314 = 1884.00Keeping = 40 mm nominal side cover

5 Design of ties:-Diameter of ties should be 1/4 of the diameter of longitudinal reinforcement subject to

minimum 6 mm. However use 6 The spacing of the ties should not exceed least of the following.

(I) Least lateral diamension. = 390 mm(II) 16 x Diameter of main bars 16 x 20 = 320 mm(III) 48 x dia of ties 48 x 6 = 288 mm

Hence provided the ties @ = 280 mm c/c. The ties will be square in shape in two size as shown in fig. using them alternately, so that longitudinal bars pass through the corners of ties.

Keep pitch of each set of ties at = 280 mm

pk_nandwana@yahoo.co.in

Asc =pA = mm2

3.14xdia2

Ast/Amm bar,

mm2

mm bars of ties.

pk_nandwana@yahoo.co.in

Column design

mm

152091

mm

163539

mmAssume)

mm2

mm2

Diameter of ties should be 1/4 of the diameter of longitudinal reinforcement subject to

The ties will be square in shape in two size as shown in fig. using them alternately, so that longitudinal bars pass through the corners of ties.

mm2

Column designName of work:- pkn

495

206 Nos bars

330

40mm cover

Square column

330

495

6.00 mtr

Foundation pad

mm

pk_nandwana@yahoo.co.in

Length effect coefficient

Height lef = 0.80L lef = 1.00L lef = 1.2L lef =1.5L lef = 2L lef =2L

case 1 case 2 case 3 case 4 case 5 case 6 case 7.

case no. Degree of end restraint of compression member1 Effectively held in position and restrained against rotation at both ends

2 Effectively held in position at both ends, restrained regainst rotation atone ends.

3 Effectivly held in position at both ends, buy notrestrained regainst rotation .

4 Effectively held in position, restrained regainst rotation atone ends. And at the other restrained against rotation but not held in position

5 Effectively held in position, restrained regainst rotation atone ends. And at the other partialy restrained against rotation but not held in position

6 Effectively held in position, at one ends but not restrained against rotation,. And at the other end restrained against rotation but not held in position

7 Effectively held in position, and restrained against rotation at one endbut not held in position nor restrained against rotation at the other end.

lef = 0.65L

VALUES OF DESIGN CONSTANTSGrade of concrete M-15 M-20 M-25 M-30 M-35 M-40 Grade of concrete

Modular Ratio 18.67 13.33 10.98 9.33 8.11 7.185 7 8.5 10 11.5 13

93.33 93.33 93.33 93.33 93.33 93.330.4 0.4 0.4 0.4 0.4 0.4

Development Length in tension0.867 0.867 0.867 0.867 0.867 0.8670.867 1.214 1.474 1.734 1.994 2.2540.714 1 1.214 1.429 1.643 1.8570.329 0.329 0.329 0.329 0.329 0.329 M 150.89 0.89 0.89 0.89 0.89 0.89 M 20

0.732 1.025 1.244 1.464 1.684 1.903 M 250.433 0.606 0.736 0.866 0.997 1.127 M 300.289 0.289 0.289 0.289 0.289 0.289 M 350.904 0.904 0.904 0.904 0.904 0.904 M 400.653 0.914 1.11 1.306 1.502 1.698 M 450.314 0.44 0.534 0.628 0.722 0.816 M 500.253 0.253 0.253 0.253 0.253 0.2530.916 0.916 0.916 0.914 0.916 0.9160.579 0.811 0.985 1.159 1.332 1.5060.23 0.322 0.391 0.46 0.53 0.599

bd M-15 M-20 M-25 M-30 M-35 M-400.18 0.18 0.19 0.2 0.2 0.2

0.25 0.22 0.22 0.23 0.23 0.23 0.230.50 0.29 0.30 0.31 0.31 0.31 0.32 M 100.75 0.34 0.35 0.36 0.37 0.37 0.38 M 151.00 0.37 0.39 0.40 0.41 0.42 0.42 M 201.25 0.40 0.42 0.44 0.45 0.45 0.46 M 251.50 0.42 0.45 0.46 0.48 0.49 0.49 M 301.75 0.44 0.47 0.49 0.50 0.52 0.52 M 352.00 0.44 0.49 0.51 0.53 0.54 0.55 M 402.25 0.44 0.51 0.53 0.55 0.56 0.57 M 452.50 0.44 0.51 0.55 0.57 0.58 0.60 M 502.75 0.44 0.51 0.56 0.58 0.60 0.62

3.00 and above 0.44 0.51 0.57 0.6 0.62 0.63

Grade of concrete M-15 M-20 M-25 M-30 M-35 M-401.6 1.8 1.9 2.2 2.3 2.5

bd (N / mm2

cbc N/mm2

m cbc

(a) st = 140

N/mm2 (Fe 250)

kcjcRc Grade of

concretePc (%)

(b) st = 190

N/mm2

kcjcRc

Pc (%)

(c ) st = 230

N/mm2 (Fe 415)

kcjcRc

Pc (%)

(d) st = 275

N/mm2 (Fe 500)

kcjcRc

Pc (%)

Permissible shear stress Table v in concrete (IS : 456-2000)100A s Permissible shear stress in concrete tv N/mm2

Grade of concrete< 0.15

Maximum shear stress c.max in concrete (IS : 456-2000)

c.max

Reiforcement %

M-20 M-20bd bd

0.15 0.18 0.18 0.150.16 0.18 0.19 0.180.17 0.18 0.2 0.210.18 0.19 0.21 0.240.19 0.19 0.22 0.270.2 0.19 0.23 0.30.21 0.2 0.24 0.320.22 0.2 0.25 0.350.23 0.2 0.26 0.380.24 0.21 0.27 0.410.25 0.21 0.28 0.440.26 0.21 0.29 0.470.27 0.22 0.30 0.50.28 0.22 0.31 0.550.29 0.22 0.32 0.60.3 0.23 0.33 0.650.31 0.23 0.34 0.70.32 0.24 0.35 0.750.33 0.24 0.36 0.820.34 0.24 0.37 0.880.35 0.25 0.38 0.940.36 0.25 0.39 1.000.37 0.25 0.4 1.080.38 0.26 0.41 1.160.39 0.26 0.42 1.250.4 0.26 0.43 1.330.41 0.27 0.44 1.410.42 0.27 0.45 1.500.43 0.27 0.46 1.630.44 0.28 0.46 1.640.45 0.28 0.47 1.750.46 0.28 0.48 1.880.47 0.29 0.49 2.000.48 0.29 0.50 2.130.49 0.29 0.51 2.250.5 0.300.51 0.300.52 0.300.53 0.300.54 0.300.55 0.310.56 0.310.57 0.310.58 0.310.59 0.31

Shear stress tc100A s 100A s

0.6 0.320.61 0.320.62 0.320.63 0.320.64 0.320.65 0.330.66 0.330.67 0.330.68 0.330.69 0.330.7 0.340.71 0.340.72 0.340.73 0.340.74 0.340.75 0.350.76 0.350.77 0.350.78 0.350.79 0.350.8 0.350.81 0.350.82 0.360.83 0.360.84 0.360.85 0.360.86 0.360.87 0.360.88 0.370.89 0.370.9 0.370.91 0.370.92 0.370.93 0.370.94 0.380.95 0.380.96 0.380.97 0.380.98 0.380.99 0.381.00 0.391.01 0.391.02 0.391.03 0.391.04 0.391.05 0.391.06 0.391.07 0.391.08 0.41.09 0.41.10 0.4

1.11 0.41.12 0.41.13 0.41.14 0.41.15 0.41.16 0.411.17 0.411.18 0.411.19 0.411.20 0.411.21 0.411.22 0.411.23 0.411.24 0.411.25 0.421.26 0.421.27 0.421.28 0.421.29 0.421.30 0.421.31 0.421.32 0.421.33 0.431.34 0.431.35 0.431.36 0.431.37 0.431.38 0.431.39 0.431.40 0.431.41 0.441.42 0.441.43 0.441.44 0.441.45 0.441.46 0.441.47 0.441.48 0.441.49 0.441.50 0.451.51 0.451.52 0.451.53 0.451.54 0.451.55 0.451.56 0.451.57 0.451.58 0.451.59 0.451.60 0.451.61 0.45

1.62 0.451.63 0.461.64 0.461.65 0.461.66 0.461.67 0.461.68 0.461.69 0.461.70 0.461.71 0.461.72 0.461.73 0.461.74 0.461.75 0.471.76 0.471.77 0.471.78 0.471.79 0.471.80 0.471.81 0.471.82 0.471.83 0.471.84 0.471.85 0.471.86 0.471.87 0.471.88 0.481.89 0.481.90 0.481.91 0.481.92 0.481.93 0.481.94 0.481.95 0.481.96 0.481.97 0.481.98 0.481.99 0.482.00 0.492.01 0.492.02 0.492.03 0.492.04 0.492.05 0.492.06 0.492.07 0.492.08 0.492.09 0.492.10 0.492.11 0.492.12 0.49

2.13 0.502.14 0.502.15 0.502.16 0.502.17 0.502.18 0.502.19 0.502.20 0.502.21 0.502.22 0.502.23 0.502.24 0.502.25 0.512.26 0.512.27 0.512.28 0.512.29 0.512.30 0.512.31 0.512.32 0.512.33 0.512.34 0.512.35 0.512.36 0.512.37 0.512.38 0.512.39 0.512.40 0.512.41 0.512.42 0.512.43 0.512.44 0.512.45 0.512.46 0.512.47 0.512.48 0.512.49 0.512.50 0.512.51 0.512.52 0.512.53 0.512.54 0.512.55 0.512.56 0.512.57 0.512.58 0.512.59 0.512.60 0.512.61 0.512.62 0.512.63 0.51

2.64 0.512.65 0.512.66 0.512.67 0.512.68 0.512.69 0.512.70 0.512.71 0.512.72 0.512.73 0.512.74 0.512.75 0.512.76 0.512.77 0.512.78 0.512.79 0.512.80 0.512.81 0.512.82 0.512.83 0.512.84 0.512.85 0.512.86 0.512.87 0.512.88 0.512.89 0.512.90 0.512.91 0.512.92 0.512.93 0.512.94 0.512.95 0.512.96 0.512.97 0.512.98 0.512.99 0.513.00 0.513.01 0.513.02 0.513.03 0.513.04 0.513.05 0.513.06 0.513.07 0.513.08 0.513.09 0.513.10 0.513.11 0.513.12 0.513.13 0.513.14 0.51

3.15 0.51

M-10 M-15 M-20 M-25 M-30 M-35 M-40 M-45 M-50-- 0.6 0.8 0.9 1 1.1 1.2 1.3 1.4

Development Length in tension

Plain M.S. Bars H.Y.S.D. Bars

0.6 58 0.96 600.8 44 1.28 450.9 39 1.44 401 35 1.6 36

1.1 32 1.76 331.2 29 1.92 30

Mod

ifica

tion

fact

ore

2.01.3 27 2.08 281.4 25 2.24 26

1.4

1.2

0.8

0.4

0.0(N/mm2) (N/mm2) (N/mm2)

3.0 300 2.5 250 -- --5.0 500 4.0 400 0.6 607.0 700 5.0 500 0.8 808.5 850 6.0 600 0.9 9010.0 1000 8.0 800 1.0 10011.5 1150 9.0 900 1.1 11013.0 1300 10.0 1000 1.2 12014.5 1450 11.0 1100 1.3 13016.0 1600 12.0 1200 1.4 140

Permissible Bond stress Table bd in concrete (IS : 456-2000)

bd (N / mm2) kd = Ld bd (N / mm2) kd = Ld

Permissible stress in concrete (IS : 456-2000)Permission stress in compression (N/mm2) Permissible stress in bond (Average) for

plain bars in tention (N/mm2)Bending cbc Direct (cc)Kg/m2 Kg/m2 in kg/m2

0.4 0.8 1.2 1.6 2Percentage of tension reinforcement

2 2.4 2.8

DATA sheetDesignDrawingEffective lenght cofficientIS_Table