column limitstate

7/28/2019 Column Limitstate

1/7

Column size [ B x D] in cms 200.0X 300.00cm

Length/Height of column(L) 12 M

Effective length= 1.50 L = 18 m

LOADS/FORCES:

Axial load on the column P= 15.00 t

Reaction of the slab=

Reaction from the conc. Load 60.00Impact factor(due to gate wt:)

Reaction due to live load=

Reactiondue to finishings=

Total Load 60.00 t

Horizontal Force= Q 10.00 t

Moment Mux 2.50 t-m

Muy 2.50 t-m

Min eccentricit L/500+b/30 136.00 mm

200cm

300cm

Grade of concrete M20

Grade of steel Fe500

DESIGN OF COLUMN

Effectively Held in position and restrained against rotation at one

end, and at other partially restrained against rotation but not held in

position

L

1,

2,

Y

X X

Y

MXX

MYY


2/7

Modulous of elasticity of steel=Es= 200000 N/mm2

Modulous of elasticity of concrete=Ec= 22361 N/mm

Cover to reinforcement:

Side Cover 35 mm

Top cover 35 mm

c/D 0.01

d 296.50 cmSection Properties:

B= 200.00cm D= 300.0cm Area= 60000sq.cm

M.I. Of column= Ixx= 2E+08 cm4

Iyy= 4.5E+08cm

4

Radius of gyration:

rxx= 57.735 cm

ryy= 86.6025 cm

Le/h= 9

Slenderness ratio=

SRxx= 31.18

Sryy= 20.78


3/7

Adjustment factor=k= 1.513 1.00

Therefore revised moments & orces=

Pu= 225.00 kN

Mux= 11.43 kN_mMuy= 11.43 kN_m

0.453fc 0.002

3/7 0.0019136.83

2E+07 N-mm4/7

Nst =0.870

y As = 434.783As

Factored load:

Pu= 22.50 tQu= 15 tMu= 11.43 t-m

Shear stress= 0.03N/mm2

Pu/fcBD= 0.002Mu/fcBD 2= 0.000

xumax/d 0.456

Reinforcement:

From chart w= 0.184Ast= 442.70 sq.cmMin steel= 480 sq.cmMax. of above two values= 480.00 sq.cm Okay

Dia of bar= 25.00 mmNo. of rods 98Area 481.06 sq.cmNo. of rods provided 98Area provided 481.06 sq.cm

Nc=0.367fc b x=

c


4/7

Pt= 0.80%

Check for shear

Shear stress= 0.25 kg/sq.cm0.025 N/mm

Permissible shear= c= 0.58 N/mm

oka

Transverse Reinforcement:

Legs 2 no

Dia 8 mm >dia of mai

Vus=Qu -cBd= 0 kgSpacing 0 cm c/c

Cosidering shear contribution of concrete 0.00 cm c/c

Not considering shear contribution of concrete,spacing= 71.75 cm c/cspacing= 25.00 cm c/c


5/7

0

100

200

300

400

500

600

0 0.001 0.002 0.003 0.004 0.005

STRESS(N/MM2)

STRAIN

STRESS VS STRAIN

Fe434.8

Fe500

Fe360.9

Fe415


6/7

Nominal Transverse Reinforcement:

220.73kN

24.53kN-m

98.10kN 200.00cm

Fe500 Fe434.8

DESIGN CURVES=0.87F

offsetstrain

stress interms of strain e

stress

(N/mm2)

offsetstrain


stress

(N/mm2)

fy fy0 0 0 0 0 0 0

0 0.80 0.002 400.00 0 0.80 0.00174 347.840.0001 0.85 0.00222 425.00 0.0001 0.85 0.00195 369.580.0003 0.90 0.00255 450.00 0.0003 0.90 0.00226 391.320.0007 0.95 0.00308 475.00 0.0007 0.95 0.00277 413.060.0010 0.98 0.00344 487.50 0.0010 0.98 0.00312 423.93

0.0020 1.00 0.0045 500.00 0.0020 1.00 0.00417 434.80

Fe415 DESIGN CURVES=0.87F

offsetstrain


stress

(N/mm2)

offsetstrain


stress

(N/mm2)

fy fy0 0.00000 0 0 0 0.00000 0

0 0.80 0.00166 332.00 0 0.80 0.00144 288.720.0001 0.85 0.00186 352.75 0.0001 0.85 0.00163 306.770.0003 0.90 0.00217 373.50 0.0003 0.90 0.00192 324.810.0007 0.95 0.00267 394.25 0.0007 0.95 0.00241 342.860.0010 0.98 0.00302 404.63 0.0010 0.98 0.00276 351.880.0020 1.00 0.00408 415.00 0.0020 1.00 0.00380 360.90

300cm X

X

Y Y


7/7

h= 300 cmEPSILON_CU= 0.0019 sy= 1.8242894

LAMBDA= 1.026251

ZONE ALPHA BETA REMARKS ALPHA BETA

2 0.296 0.373

-0.865 0.358

3,4 & 4A 0.364 0.416 0.364 0.416

5 0.165 -0.118

2

3

1345.0

13414

002.0i.e.,

1

cu

FOR

3145.0

134

222

0035.00.002i.e.,

1

cu

FOR

2

21

4145.0

2

2

421

85.24

7

3

hx

h

37

4

column limitstate

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