Design of Base Plate for BS5950

4.4 BASE PLATE AND ANCHOR BOLT CHECK DESIGN OF BASE PLATE STRUCTURE: XFR AREA J Column Mark : UC-203 UC203X203X46 1. DESIGN FORCES SUMMARY UC-203

STAAD OUTPUT

DESCRIPTION

Fx

Fy

(kN)

(kN)

DESIGN FORCES Fz

Condition

Beam

L/C

NODE

Max Compression

2027

456

255

232.8

30.2

Max Tension

2001

595

245

-13.9

Max Shear

2030

595

256

-7.2

(Fy2+Fz2)0.5 Friction (f)

Axial (F)

(kN)

F = Fx (kN)

Q (kN)

f=0.45F (kN)

Shear Q - f (kN)

3.3

232.8

30.4

104.8

0.0

10.5

0.0

-13.9

10.5

0.0

10.5

22.9

-0.5

-7.2

22.9

0.0

22.9

F = Fc (Axial Compression) if value is positive, F = Ft (Axial Tension) if values is negative 2. MATERIAL PROPERTY AND DIMENSION Steel Column :

Base Plate :

Anchor Bolt :

D=

203.2 mm

B=

203.6 mm

t=

7.2 mm

T=

11.0 mm

Pyp =

265.0 Mpa (S275)

Dp =

250.0 mm

Bp =

250.0 mm

tp =

22.0 mm

Grade : db =

4.6 24.0 mm

n=

2.0 pcs

Effective Area per bolt (Aeperbolt) =

353.0 mm2

Effective Area of bolts (Aebolts) =

706.0 mm2

3. CHECK FOR CONCRETE BEARING STRENGTH (4.13.1 of BS 5950-1:2000) fcu =

30.0 Mpa

0.6fcu =

18.0 Mpa

Fc =

Fc / BpDp =

3.7 Mpa < 0.6fcu OK!

Areq = Fc / 0.6Fcu = 12,933.3 mm2

232.8 kN (Maximum Compression Force)

4. CHECK FOR BASE PLATE THICKNESS BY EFFECTIVE AREA METHOD (sec 4.13.2.2 of BS 5950-1:2000)

0.5

base plate thickness (tpreq) = c (3x0.6f cu/Pyp) 2

effective area (Aeff) = 4c1 + c1(Percol) + Acol (Assuming no Overlap of Effective Area)

Column Perimeter (Percol) =

1,190.0 mm

Area of Steel Column Acol =

5,870.0 mm2

effective area (Aeff) = 4c2 2 + 2(D + B)c2 + DB (Assuming Effective Area has Overlap) solving for c by equating Aeff to Areq :

12,933.3

=

12,933.3 (D-2T )/2 =

90.6

=

4c12 + 2

4c2 +

1,190.0c1 + 5,870.0

c1 =

5.82

mm

813.6c2 + 41,371.5

c2 =

-44.84

mm

mm > c1, effective area has no overlap (use value of c1 for c)

D +2c =

214.84

mm < Dp

B + 2c =

215.24

mm < Bp

Hence the calculated value of c is valid. c=

5.82

mm

tpreq =

2.7

mm < tp, OK!

5. ANCHOR BOLT STRESS CHECK 5.1 Design Strength of Anchor Bolts pt =

240

Mpa, tension strength of anchor bolt

ps =

160

Mpa, shear strength of anchor bolt

5.2 Capacity of Ancor Bolts Tension Capacity of Anchor Bolts (Pt) =

162.8

kN

Shear Capacity of Anchor Bolts (Ps) =

108.6

kN

5.3 Combined Tension and Shear Check Due to Maximum Tension, Load Case # : Ft =

13.9

595

Due to Maximum Shear, Load Case # :

kN

V=

10.5

kN

Ft / Pt =

0.09

< 1.0 OK!

Ft =

595 kN

V=

22.9

kN

Ft / Pt =

0.04

< 1.0 OK!

0.21

< 1.0, OK!

0.05

<1.0, OK!

V/Ps =

0.10

< 1.0 OK!

V/Ps =

(Ft/Pt)2 + (V/Ps)2 =

0.02

<1.0, OK!

(Ft/Pt) + (V/Ps) =

2

7.2

2