Mathcad - BASEPLATE DESIGN -10.pdf

Client : xxxxxx Project :xxxxx Tent Type : 10.6X6X2.4M TENT BASEPLATE & ANCHOR BOLT CALCULATION PIPE COLUMN I. Design Criteria A. Design Code CODE : BS 5950-1-2000 B. Service Loads V1 := 7.9 ⋅ kN

Shear force on a column

Pu := 15.94kN

Total Compressive column load

Pu = 1.594 × 10 ⋅ N

Mu := 37.36 ⋅ kN ⋅ m

Total Moment

Mu = 3.736 × 10 ⋅ N ⋅ mm

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C. Properties C.1 For concrete pedestal: fc := 30MPa

concrete cylinder strength @ 28 days

fc = 30 ⋅

D1 := 450mm

Pedestal Dinension 1

D2 := 450mm

Pedestal Dimension 2

A2 := D1 ⋅ D2

Pedestal Area

dae := 50mm

Anchor rod edge distance on baseplate

N 2

mm

C.2 Size of Steel Column dp := 219.1 ⋅ mm

diameter of column

tw := 6.4 ⋅ mm

thickness of column

C.3 For Steel Base Plate : Fy := 275 ⋅ MPa

yield strength of steel

Fy = 275 ⋅ MPa

For Anchor bolts : Fu := 640 ⋅ MPa

Anchor bolt ultimate strength Grade 8.8 based on Table 34 BS 5950-1-200

ϕab := 20mm

anchor bolt diameter

Ft := 0.75 ⋅ Fu ⋅

( π ⋅ ϕab2) 4

Allowable tensile strength of bolt

1

Ft = 150.796 ⋅ kN

D. Base Plate Design D. 1. Design of Baseplate without Stiffener Plate B1 := 350mm m1 :=

Width of base plate

B1 − − dp

baseplate cantilver projections from the edge

2 2

Aprov := B1

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2

area provided

Aprov = 1.225 × 10 ⋅ mm

eccentricity

e1 = 2.344m

Determine e and critical e e1 :=

Mu Pu

⎛

A2

⎝

Aprov

fpmax := max ⎜0.35 ⋅ fc ⋅

ecrit :=

B1

⎞

, 0.7 ⋅ fc⎟ = 21 ⋅

= 0.058m

6

N 2

⎠

mm maximum allowable bearing pressure

fpmax = 21 ⋅

N 2

mm

ecrit = 0.058m

Crtical eccentricity

echeck := if ( e1 < ecrit , "Use Small Moment Calculation" , "Use large moment calculation" ) echeck = "Use large moment calculation" dbc :=

B1 − dp

= 65.45 ⋅ mm

2

Mu − Pu ⋅ Ts1 := dbc +

As1 := 3 ⋅

EDGE distance of the plate measured from side of the column Tension on the bolts

dp

2 = 203.507 ⋅ kN dp 2

( B1 − dp) 2

= 0.196m

Bearing length

εcheck ( Ts1=+ Pu) N fcb := = 1.597 ⋅ 2 2As1 B1 mm

bearing pressure at the end of the plate

εcheck := if ( fcb > fpmax , "Increase baseplate Dimension" , "Baseplate dimension is OK" ) εcheck = "Baseplate dimension is OK" 2

Mmaxbb := 0.85 ⋅ fcb ⋅ dae ⋅ B1 = 0.024m ⋅

tbpmax :=

6 ⋅ Mmaxbb 1.2Fy

N 2

mm

= 20.78 ⋅ mm THICKNESS OF BASE PLATE WITHOUT STFFENER PLATE

tbp1final := tbpmax + 2mm = 22.78 ⋅ mm

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D. 2. Design of base plate with stiffener D.2.1 Design of base plate B1use := 350mm

bs :=

2⋅

B1use

rs :=

ls bs

dp 2

= 247.487 ⋅ mm

= 0.557

Ts := dbc +

As2 := 3 ⋅

spacing of gusset plate

= 137.937 ⋅ mm

Mu − Pu ⋅

fc1 :=

2

4

ls := bs −

size of base plate used

Timoshenko Ratio (Reference: Design of Monopole Column by Daniel Horn)

dp 2

dp

= 203.507 ⋅ kN

2

( B1use − dp) 2

( Ts + Pu) 2As2 B1use

= 196.35 ⋅ mm

= 1.597 ⋅

Bearing length

N 2

mm 2

Mmax1 := 0.0467 ⋅ fc1 ⋅ bs = 4.567m ⋅ 2

N mm

Mmax2 := − 0.287 ⋅ fc1 ⋅ ls = − 8.719 m ⋅

tbp1 :=

tbp2 :=

6 ⋅ Mmax1 1.2Fy

Moment at the edge

N mm

Moment at the face of the column thickness of base plate based on Mmax1

= 9.112 ⋅ mm

6 ⋅ Mmax2 1.2Fy

thickness of base plate based on Mmax2

= 12.59 ⋅ mm

tbpfinal := max ( tbp1 , tbp2) + 2mm THICKNESS OF BASE PLATE WITH STIFFENER PLATE

tbpfinal = 14.59 ⋅ mm

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D. 2.2. DESIGN OF STIFFENER PLATE Stiffener Plate Properties tgusset := 8mm

thickness of the gusset plate

bgusset := 65mm

bottom length of stiffner plate

agusset := 150mm

height of the stiffner plate

Calculation for Shear and Moment affecting the plate

As3 := As2 −

( B1use − dp) 2

= 130.9 ⋅ mm

⎛ As3 ⎞ ⎟ ⋅ 0.5 ⋅ As2 ⋅ B1use = 36.575⋅ kN ⎝ As2 ⎠

Fvgusset := fc1 ⋅ ⎜

shear on gusset plate

⎛ As3 ⎞ ⎟ ⎝ As2 ⎠

fc2 := fc1 ⋅ ⎜

Fmgusset :=

( B1use − dp) ⎛ fc1 + fc2 ⎞ ( B1use − dp) ⋅ B1use ⋅ 0.6 ⋅ ⎜ ⎟⋅ 2 2 ⎝ 2 ⎠ 6

Fmgusset = 1.197 × 10 ⋅ N ⋅ mm

Moment on gusset plate

⎛ bgusset ⎞ ⎛ bgusset ⎞ ⎟ + 1.27 ⋅ ⎜ ⎟ ⎝ agusset ⎠ ⎝ agusset ⎠

zv := 1.39 − 2.2 ⋅ ⎜

2

⎛ bgusset ⎞ ⎟ ⎝ agusset ⎠

3

+ 0.25 ⋅ ⎜

zv = 0.695

shape factor of gusset plate

fvgusset := 0.9 ⋅ Fy ⋅ zv ⋅ bgusset ⋅ tgusset = 89.509 ⋅ kN

shear resitance of gusset plate

fmgusset := Fy ⋅

tgusset ⋅ agusset 6

2

6

= 8.25 × 10 ⋅ N ⋅ mm

moment resistance of gusset plate

spcheck1 := if ( fvgusset > Fvgusset , "gusset plate passed in shear" , "increase dimension" )

spcheck1 = "gusset plate passed in shear" spcheck2 := if ( fmgusset > Fmgusset , "gusset plate passed in moment" , "increase dimension" )

spcheck2 = "gusset plate passed in moment"

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E. Anchor BOLT Design Ts

n bt :=

Number of Anchor Bolts Required

Ft

n bt = 1.35 Abl := 17 ⋅ ϕab = 340 ⋅ mm

minimum embedment length

n buse := 2

Number of Anchor bolts used

sp :=

B1use − 2.dae

spacing of anchor bolt

n buse

sp = 125 ⋅ mm

LAB :=

Ts nbuse

0.7 ⋅ fc ⋅ ϕab

= 242.271 ⋅ mm

LABBENDmin := 3.5 ⋅ ϕab = 70 ⋅ mm

Anchor bolt embedment length design

MINIMUM END BEND OF THE ANCHOR BOLT

LABTOT := max ( LAB , Abl) + 2 ⋅ ϕab + tbpfinal = 394.59 ⋅ mm

LABTOT = 394.59 ⋅ mm

REQUIRED TOTAL LENGTH OF THE ANCHOR BOLT

F. SUMMARY Based on the above calculations, we will be using the following sections 1. 4sets -550mm anchor bolt length with 70mm bend 2. 350x350xx16mm Base Plate with Stffiner plate of 150x65x10mm

-------------------------END OF BASE PLATE CALCULATION-----------------------

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