151702959 built up steel column

7/28/2019 151702959 Built Up Steel Column

1/26

A.Intermediateframe

6.A.1 Loads:

6. COLUMN

-Checking the member for the following combination of loads:

Vmax = Fy,max = 780 kN -maxm. shear force

-the beam is connected at the face of column. Forces to be tranferred at the centroid of column:

Offset, o = 750 mm -offset of column in major axis directn.

6.A.2 Sectional properties & end conditions:

Section: 4 x 300 NB 6 THK. TATA STRUCTURA

Properties: Individualmember-

##

Izz = Iyy = 79288969 mm yCompositesection-

It = 158.58 x10

Acomp. = 25143.8 mm

mm4

z

##

Self-wt.comp = 197.4 kg/m

4

Fig. 4.a Columnc/s

Izz,comp. = 14.46 x10

Iyy,comp. = 1.32 x10

mm

mm4

x10

9

mm6 4

-warping const.

Self-wt. = 49.34 kg/m

Outer diameter of pipe = 323.9 mm

Thickness = 6.3 mm

Inner diameter of pipe

A

=

=

311.3 mm

6286 mm2

For load case 1.2 [DL+OL+LL+WL_135DEG], for member no. 401 in STAAD file

Case 2: Fx = 710 kN -maxm. axial compression

Mz = 1650 kN-m -moment

For load case 1.5 [DL+OL+WL_0DEG], for member no. 401 in STAAD file

Case 1: Fx = -750 kN -maxm. axial tension



2/26

It,comp = 15.78 x10 mm

-torsional constant

zpz,comp = 18.86 x10

zpy,comp = 5.03 x10

zez,comp = 15.86 x10

zey,comp = 3.65 x10

rz = 758.36 mm

ry = 229.38 mm

fy = 310 MPa

fu = 450 MPa

mm3

mm3 mm3 mm3

-plastic section modulus

-elastic section modulus

-radius of gyration

Structural restrain:L = 12000 mm -unrestrained length

LLT = 0.8 L

= 12000 mm

2

24000 mm

07]

0.5

2007], (full torsionall warping restrain)

-for effective length of compression member (one end fixed, other free)

rr2

I

y Iw

GIt LLT 2

-elastic critical moment

Mcr =


3/26

LLT 2

Iy +

rr2

I

y

[Annex. E-1.1, IS 800- 2007]

E

G

-extreme fibre bending

compressive stress

Section Classification:

51.4

0.90

1462.'. b = 0.84 As section is semi-compact

Mdz = bzpfbd

= 4468.4 kN-m

-moment capacity @ major axis

Mz,max = Mz + (F x o) F- axial force, o-offset

6.A.4 Tensile strength:-considering yeilding of gross section

Td = Agfy/mo

[As per Cl. 6.2 of IS 800- 2007]

= 7086.0 kN -design tensile strength

Tmax = 750 kN -maxm. axial tension

Td > Tmax OK

6.A.5 Compressive strength:

= 2292.5 kN-m for case I

= 2182.5 kN-m for case II

Mdz > Mz,max OK

Mcr = 150655.8 kN-m

fcr,b =

=

Mcr / Zpx

7989.0 MPa

.'. fbd = 281.8 MPa

= 200000 MPa -Young's modulus

= 79300 MPa -modulus of rigidity


4/26

1.05 x (kL/rmin) = 109.86 mm -for laced column

07]

Buckling class = c

fc = 101.19 MPa

tions as per Table-

00- 2007]

of IS 800- 2007]

Pd = 2544.3 kN -design compressive strength

Pmax = 710.0 kN -maxm. axial compression Pd > Pmax OK

COMBINEDCHECKS:

6.A.6 Section strength: [As per Sec. 9.3.1 of IS 800- 2007]

N My

Mz

1.0

Nd + Mdy + Mdz

Nd + Mdy + Mdz

= 0.59 -for Case II

6.A.7 Overall member strength:

A) Bending + Axial tension [As per Sec. 9.3.2.1, IS 800- 2007]

NMy = 0.62 OK -for Case I

N = 750 kN -axial tension

My=

=

710 kN

0 kN-m

-axial compression

-no moment acting @ minor axis


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Meff = [M-TZec/A] Md

= 1 -T & M cannot vary independently Meff = 2292.50 kN-m

Md > Meff OK

B) Bending + Axial compression [As per Sec. 9.3.2.2, IS 800- 2007]

p pdy +

Cmy My Ky

Mdy

+ KLT

Mz Mdz

1.0

Cmy My

Ky


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+ Kz

Cmz Mz

1.0

pdz + 0.6

Mdy

Mdz

KLT =

LT ny

1

CmLT

0.25

Ky = 1+(y-0.2)ny 1 + 0.8ny

Kz = 1+(z-0.2)nz 1 + 0.8nz


7/26

0.1ny

1 C 0.25

z

=

y =

fcc =

fy

fcc

rr2

kL 2

r

fcc,z = 1970.9 MPa

0.40

P/Pd

0.279


8/26

fy

LT =

fcr,b

fcr,b = 7989.0 MPa

LT = 0.20

CmLT = 0.7

Cmy = Cmz = 0.7

IS 800- 2007]

M1 = 0.2)

p pdy

+ Ky

CmyMy Mdy

Mz

+ KLT

Ky = Kz = 1.1

KLT = 0.99

My = 0 kN-m -no moment acting @ minor axis


9/26

dz

= 0.76 OK

CmyMy

K

K Cmz Mz

= 0.64 OK

pdz + 0.6 y

Mdy +

z Mdz

6.A.8 Design of Lacings:

-Lacings are designed to take the shear force on the column section Lacings would be of two types:

i) Primary: these take shear force obtained by analysis acting along the y directn. (Fig. 4.a)ii) Secondary: these take shear = 2.5% of axial load along the z directn. (Fig. 4.a)

Fy s P

(shear)

% of axial

orce

1500 400


10/26

Fig.4.b-Lacingarrangement

i) Primary Lacings:

Loads-

Fy,max = 780 kN -maxm. SF in the column

-c/s area

Ixx = Iyy = 7.33 x10

It = 14.65 x10

mm4

mm4

-second moment of area

-torsional const.

zp = (d 3

- d 3)/6 -plastic section modulus

= 116.10 x103 mm3

ze = 89 x10

mm3


rmin = 56.8 mm -radius of gyration

fy = 310 MPa -grade of steel fu = 450 MPa

Structuralrestrain-k = 1

OtherParameters-

-both ends pinned, as lacings take only axial loads

s = 3000 mm -spacing of lacing system

P = 551.5 kN

= 45

ks/r1 50

0.7 (kL/rmin)comp.

-axial compression on each lacing element

[As per Cl. 7.6.5.1, IS 800- 2007]

r1 - radius of gyration of individual member being laced together

0.7 (kL/rmin)comp. = 73.24 mm (kL/rmin)comp. -for the composite section

r1 = 112.31 mm

ks/r1 = 26.7 mm OK

Compressioncapacity-

L = 2121 mm

kL/rmin = 37.35 mm

-c/c length of each lacing member


A

=

=

156.1 mm

2270 mm2


Section: 150 NB 4.5 THK.

Properties:

TATA STRUCTURA

Outer diameter of pipe = 165.1 mmThickness = 4.5 mm


11/26

Buckling class = a

fc = 263.15 MPa

ions as per Table-

00- 2007]

of IS 800- 2007]



ii) Secondary Lacings:

Loads-

P = 47.6 kN -2.5% of (P + M/d)

Section: 32 NB 3.2 THK. TATA STRUCTURA

Properties:

Outer diameter of pipe = 33.7 mm Thickness = 3.2 mm

Inner diameter of pipe = 27.3 mm

A = 307 mm2 -c/s area Self-wt. = 2.41 kg/m

Ixx = Iyy = 0.04 x10

It = 0.07 x10

mm4

mm4


-torsional const.

zp = (d 3


x103 mm3

z x103

mm3


rminfy fu

mm -radius of gyration

MPa -grade of steel MPa

Structuralrestrain-k

OtherParameters-

-considering both ends pinned

s = 750 mm -spacing of lacing system @ z-axis

P = 32.6 kN

=

=

=

10.8

310

450

= 1

=

=

2.99

2


12/26

= 43

ks/r1 50

0.7 (kL/rmin)comp.


[As per Cl. 7.6.5.1, IS 800- 2007]



r1 = 112.31 mm

ks/r1 = 6.7 mm OK


L = 548 mm

kL/rmin = 50.57 mm


Buckling class = a

fc = 247.06 MPa

ions as per Table-

00- 2007]

of IS 800- 2007]



6.A.9 Welded connection between lacing & column:

i) Primary Lacing-

-Using fillet weld for the joint

Weld capacity =

fu

y

mw

Weld thickness = 4 mm

tt

mw

=

=

2.83 mm

1.25

Grade of weld=

=

32.6 kN

Fe 540

-for secondary lacing

fu = 540 MPa

fy = 410 MPa

Force to be transmitted, Fmax = 551.5 kN -for primary lacing


13/26

t

t

N/mm

-effective throat thickness of weld

-for shop fabrications= 587.9 N/mm

m

-using welded gusset plated connection for the member:

m

m

OK

Fig.4.c-Typicalweldedgussetplatedconnection

ii) Secondary Lacing-



-for shop fabrications

6.A.10 Welded connection between gusset plate & column CHS:

-Gusset plate is provided for primary lacings

-Gusset plate transfers force from lacings to column members

-thickness of gusset plate

Grade of weld = Fe 540

fu = 540 MPa

fy = 410 MPa


Weld capacity =

fy t =

=

410 MPa

6 mm


tt

mw

=

=

4.24 mm

1.25

Force transferred, F = 551.5 kN

Grade of plate = Fe 540

fu = 540 MPa

tt

mw

=

=

2.12 mm

1.25

Weld capacity = 440.9 N/mm

Weld length reqd.

Provided weld length

=

=

74.0 mm

105.9 mmOK



14/26

fu

y

mw

t

t

N/mm


-for shop fabrications

B.Endframe

6.B.1 Loads:

-Checking the member for the following combination of loads:

Vmax = Fy,max = 240 kN -maxm. shear force

-the beam is connected at the face of column. Forces to be tranferred at the centroid of column:

Offset, o = 750 mm -offset of column in major axis directn.

6.B.2 Sectional properties & end conditions:

Section: 4 x 200 NB 6 THK. TATA STRUCTURAProperties: Individualmember-

##

Izz = Iyy = 22819474 mm y

Thickness = 6 mm


A

=

=

207.1 mm

4017 mm2





For load case 1.2 [DL+OL+LL+WL_135DEG], for member no. 401 in STAAD file

Case 2: Fx

= 245 kN -maxm. axial compression

Provided weld length = 700 mm -providing weld on both sides

For load case 1.5 [DL+OL+WL_0DEG], for member no. 401 in STAAD file

Case 1: Fx = -230 kN -maxm. axial tension

= 1058.2 N/mm

Weld length reqd. = 521.2l = 350.0 mm -length of plate


15/26

Compositesection-

It = 45.64 x10

Acomp. = 16067.36 mm

mm4

z

##

Self-wt.comp = 126.1 kg/m4

Fig. 4.a Columnc/s

Izz,comp. = 9.13 x10

Iyy,comp. = 0.73 x10

mm

mm4

x10

9

mm6 4

-warping const.

It,comp = 9.86 x10 mm

-torsional constant

zpz,comp = 12.05 x10

zpy,comp = 3.21 x10

zez,comp = 10.62 x10

zey,comp = 2.37 x10

rz = 753.78 mm

ry = 213.73 mm

fy = 310 MPa

fu = 450 MPa

mm3

mm3 mm3 mm3

-plastic section modulus


-radius of gyration

Structural restrain:

L = 12000 mm -unrestrained length

LLT = 0.8 L

= 12000 mm

2

24000 mm

07]

0.5

2007], (full torsional


16/26

l warping restrain)

-for effective length of compression member (one end fixed, other free)

rr2

I

y Iw

GIt LLT 2

-elastic critical moment

Mcr =

LLT 2

Iy +

rr2

I

y

[Annex. E-1.1, IS 800- 2007]

E

G

= 7361.5 MPa

.'. fbd = 281.8 MPa-extreme fibre bending

compressive stress

Section Classification: [Table 2, IS 800- 2007]

D/t = 36.5

0.90

D/t < 522 Section is compact

As section is compact

fcr,b = Mcr / Zpx

= 200000 MPa -Young's modulus

= 79300 MPa -modulus of rigidity

Mcr = 88710.3 kN-m


17/26

Mdz = bzpfbd

= 3395.8 kN-m

-moment capacity @ major axis

Mz,max = Mz + (F x o) F- axial force, o-offset

Mdz > Mz,max OK

6.B.4 Tensile strength:

-considering yeilding of gross section

Td = Agfy/mo

[As per Cl. 6.2 of IS 800- 2007]

= 4528.1 kN -design tensile strength

Tmax = 230 kN -maxm. axial tension

Td > Tmax OK

6.B.5 Compressive strength:

1.05 x (kL/rmin) = 117.91 mm -for laced column

07]

Buckling class = c

fc = 90.92 MPa

tions as per Table-

00- 2007]

of IS 800- 2007]



COMBINEDCHECKS:

6.B.6 Section strength: [As per Sec. 9.3.1 of IS 800- 2007]

N My

Mz

1.0

= 647.5 kN-m for case I

= 693.8 kN-m for case II


18/26

Nd + Mdy + Mdz

Nd + Mdy + Mdz

= 0.26 -for Case II

6.B.7 Overall member strength:

A) Bending + Axial tension [As per Sec. 9.3.2.1, IS 800- 2007]

Meff = [M-TZec/A] Md

= 1 -T & M cannot vary independently Meff = 647.50 kN-m

Md > Meff OK

B) Bending + Axial compression [As per Sec. 9.3.2.2, IS 800- 2007]

p pdy +

Cmy My Ky

Mdy

+ KLT

NMy = 0.24 OK -for Case I

N = 230 kN -axial tension

My==

245 kN0 kN-m

-axial compression-no moment acting @ minor axis


19/26

Mz Mdz

1.0

Cmy My

Ky

+ Kz

Cmz Mz

1.0

pdz + 0.6

Mdy


20/26

Mdz

KLT =

LT ny

1

CmLT

0.25

0.1ny

1 C 0.25

z

=

y =

fcc =

fy

Ky = 1+(y-0.2)ny 1 + 0.8ny

Kz = 1+(z-0.2)nz 1 + 0.8nz


21/26

fcc

rr2

kL 2

r

fcc,z = 1947.1 MPa

0.40

P/Pd

0.168

fy

LT =

fcr,b

fcr,b = 7361.5 MPa

LT = 0.21

CmLT = 0.7

Cmy = Cmz = 0.7

IS 800- 2007]

M1 = 0.2)

Ky = Kz = 1.0

KLT = 0.99

My = 0 kN-m -no moment acting @ minor axis


22/26

p pdy

+ Ky

CmyMy Mdy

Mz

+ KLT

dz

= 0.37 OK

CmyMy

K

K Cmz Mz

= 0.32 OK


23/26

pdz + 0.6 y

Mdy +

z Mdz

6.B.8 Design of Lacings:

-Lacings are designed to take the shear force on the column section Lacings would be of two types:

i) Primary: these take shear force obtained by analysis acting along the y directn. (Fig. 4.a)

ii) Secondary: these take shear = 2.5% of axial load along the z directn. (Fig. 4.a)

Fy s P

(shear)

% of axial

orce

1500 400

i) Primary Lacings:

Loads-

Fy,max = 240 kN -maxm. SF in the column

-c/s area

Ixx = Iyy = 0.96 x10

It = 1.93 x10

mm4

mm4


-torsional const.

zp = (d 3


= 28.85 x103 mm3


A

=

=

80.9 mm

1067 mm2


Section: 80 NB 3.2 THK.

Properties:

TATA STRUCTURA


Thickness = 4 mm


24/26

ze = 22 x10

mm3


rmin = 30.0 mm -radius of gyration

fy = 310 MPa -grade of steel fu = 450 MPa

Structuralrestrain-k = 1

OtherParameters-

-both ends pinned, as lacings take only axial loads

s = 3000 mm -spacing of lacing system

P = 169.7 kN

= 45

ks/r1 50

0.7 (kL/rmin)comp.


[As per Cl. 7.6.5.1, IS 800- 2007]



r1 = 75.37 mm

ks/r1 = 39.8 mm OK


L = 2121 mm

kL/rmin = 70.59 mm


Buckling class = a

fc = 209.58 MPa

ions as per Table-

00- 2007]

of IS 800- 2007]



ii) Secondary Lacings:

Loads-

P = 14.6 kN -2.5% of (P + M/d)

Section: 32 NB 2.6 THK. TATA STRUCTURA

Properties:

Outer diameter of pipe = 33.7 mm Thickness = 3.2 mm

Inner diameter of pipe = 27.3 mm

A = 307 mm2 -c/s area Self-wt. = 2.41 kg/m

Ixx = Iyy = 0.04 x10

It = 0.07 x10

mm4

mm4


25/26


-torsional const.

zp = (d 3


x103 mm3

z x103

mm3


rmin

fy fu

mm -radius of gyration

MPa -grade of steel MPa

Structuralrestrain-k

OtherParameters-

-considering both ends pinned

s = 750 mm -spacing of lacing system @ z-axis

P = 10.0 kN

= 43

ks/r1 50

0.7 (kL/rmin)comp.


[As per Cl. 7.6.5.1, IS 800- 2007]



r1 = 75.37 mm

ks/r1 = 10.0 mm OK


L = 548 mm

kL/rmin

= 50.57 mm-c/c length of each lacing member

Buckling class = a

fc = 247.06 MPa

ions as per Table-

00- 2007]

of IS 800- 2007]


=

=

=

10.8

310

450

= 1

=

=

2.99

2


26/26


6.B.9 Welded connection between lacing & column:

i) Primary Lacing-

-Using full penetration groove weld for the joint


tt = 4 mm


mw = 1.25 -for shop fabrications

fu

Weld capacity =

3 y

mw

t

t

N/mm

= 831.4 N/mm

Weld length reqd. = 204.1 mm

Provided weld length = 279.3 mm OK

-providing weld around the whole

circumference of the tube

ii) Secondary Lacing-

Weld thickness = 3 mm -fillet weld

tt = 2.12 mm

-effective throat thickness of weld-for shop fabrications

mw = 1.25

Weld capacity = 440.9

Weld length reqd.

Provided weld length

=

=

22.7 mm

105.9 mmOK

Grade of weld=

=

10.0 kN

Fe 540

-for secondary lacing

fu = 540 MPafy = 410 MPa

Force to be transmitted, Fmax = 169.7 kN -for primary lacing

151702959 built up steel column

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