Single Footing Design - Telecomm, Transmission & Guyed Tower & Pole - TIA 222F & ACI

Foot Plate

DESIGN CALCULATION OF

Single footing - Subjected to Compressive & Tensile Force (±P), Shear Force (±V) (No Moment) Design Code TIA/EIA 222 F, ACI 318-99)

A.

B.

C.

GENERAL 1 Tower Height (m) 2 Soil Class

= =

LOADINGS, Unfactored Vertical load (kN) Condition Max Compression Max Tension

= =

MATERIAL PROPERTIES 1 Soil angle of friction / frustum angle 2 Soil density 3 Allowable soil bearing cap 4 5 6 7 8

D.

All VALUES ARE UNFACTORED Hx - kN Hy - kN F - kN 47.939 46.269 745.950 -48.016 -48.228 -617.464

25 0 3 1600 kg/m 2 kg/cm 1

= =

(σall)

=

(gc) Sur (Φ') (ΦT)

= = = = =

(BO) (hp) or (T) (h) (h1)

= = = =

(bc)

=

0.6 m

(Bb) (hp+h)

= =

7 m 2.95 m

3 Chimney / Pedestal size/width 4 Min of tower base width 5 Total depth

m

(Φ) (gs)

Concrete density Surcharge (If any) Soil Type Soil angle of friction (Drained condition) Soil angle of friction (Undrained condition)

DIMENSIONS 1 Pad / Footing Footing Outer width / Length Footing Thickness 2 Overall soil depth, above pad Height of chimney above GL

72

[But this value should be EXACTLY 30º per TIA 222F] 3 = 15.70 kN/m [But this value… EXACTLY 16 2 kN/m = 98.10

3

3

2400 kg/m = 23.54 kN/m 2 2 0.1 kg/cm = 9.81 kN/m Clean fine sand, silty or clayey fine to medium sand. 25 0 0

4.25 0.5 2.45 0.4

m m m m

Ba

h1 Φ

h hp

M=HR.h

Bo

Bt

5 Checking of free space between soil frustum, at GL Add, width, due to soil frustum

(Ba)

=

(sf)

=

Effective add width, due to soil frustum

(Ba')

=

1.14 m

Effective soil frustum angle Width total frustum

(Φ') (Bt)

= =

25 6.53

(Vch1)

=

(Vch2)

=

(Vp) (Vch1+Vch2)

= =

(Cw) (Vc)

= =

3 9.03125 m 3 1.03 m 3 0.00 m 3 10.06 m

(W c)

=

236.79 kN

(Vcone)

=

(Vsoil)

=

3 29.05 m 3 m 43.37

(Vs)

=

3 72.42 m

W s)

=

1137 kN

Qu

=

3 14.73 m

Free space

E.

UPLIFT CAPACITY 1 Concrete Volume above GL Volume within frustum Volume below frustum Vol. chimney / Pedestal Counter Weight (Not Surcharge) Vol concrete total Concrete weigth 2 Soil Weight Calculation A Method A Volume Soil Cone Volume of Soil just above the footing Total Volume Soil Soil weight B Method B Volume Soil Cone

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(Method A,

12/16/2013

1.14 m -1.61

<

0

use eff frustum angle

O

3

0.14 m 3 0.882 m

Eq OK

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Foot Plate

Volume of Soil just above the footing Total Volume Soil (Method B,

Soil weight Total Soil Volume (Smaller of Method A & B) So Final Soil weight 3 Checking of uplift Capacity Total weight resisting uplift

(Vsoil)

=

(Vs)

=

3 43.37 m 3 58.10 m

W s)

=

912 kN

(W s)

=

912 kN 912 kN 1149 kN

[Coefficient of lateral earth pressure K = 0.5]

(W c+Ws)

=

>

617.464 kN

222F

Code provision for uplift Check - 1

(W c+Ws)/1.5

=

766

>

617.464

...OK

222F

Code provision for uplift Check - 2

(W c/1.25+Ws/2)

=

645

>

617.464

...OK

745.95 kN

F.

BEARING CAPACITY 1 Vertical Load from tower base (Downward) Concrete weight (Excluding soil weight) Maximum vertical load - (Compression Force) Minimum vertical load - (Tension Force) Wind load combined with Load Combination?

(Fc)

=

(W c')

=

N max N min

= = =

1.86

78.93 kN 824.88 kN Tension force need NOT to be checked for bearing, if compression passes Yes

2 Bending momnet, due to Sliding / Shear force

A

q MAX

B

My = 160.60 kN e1 or ex = 0.195 Bo/6 = 0.708 Mx = 155.00 kN e2 or ey = 0.188 Bo/6 = 0.708 Remember, Here footing has been designed for ONE WAY ECCENTRICITY (Uniaxial Moment), SO it should be checked for Mx,ex first then again in another calculation the footing should be checked for My, ey (Here calculation for My, ey has not been shown)

ì æö 6e ï P ç÷1 + L L (σmax) èø ï ++-£ q s ( 0.15 w s ) T , for e qs =í BL 6 ï T 2P L ++-> q s ( 0.15 w s ) T , for e ï (σmin) 3 B (0.5 L e ) 6 î

=

67.59

<

130.47 kN/m2

...OK

= = =

surcharge Footing thickness 43.36 <

130.47 kN/m2

...OK

For TWO WAY ECCENTRICITY (Biaxial Moment) , below eq 1 must be satisfied FIRST. Most tower has biaxial moment for single footing / Pile. If eq 1) passes then use eq 2) to calculate the footing's 4 corner pressure, otherwise increase footing size. If this don’t satisfy then increase footing size

Eq 1)

Here,

(σmax) SLIDING

B and L

=

2 70.34 kN/m

<

2 130.47 kN/m

...OK

(Sliding is important for Tower, specially Monopole or guyed pole or tapered pole)

Coefficient of friction, From table Coefficient of friction, From Eq

μ μ

Finally use Allowable Coefficient of friction (SF = 1.5 ~ 2)

μ μa μa

195993455.xls.ms_office

Weigth of footing

c1 & c2

( another eq is σ max = P / Az + P*e1*c1/I1 + P*e2*c2/I2)

Eq 2)

G.

Wf

= = = = = =

12/16/2013

0.35 - 0.45 Input manually tan (0.7*φ') 0.296 0.35 μ / SF 0.233

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Foot Plate

λa λa

Alloable equivalent passive fluid density

= =

Page 278, Donald P. Coduto Foundation Design, Pprinciples and Practices

113.193 lb/ft2

Note Factor of safety for μ is 1.5 to 2 Note Factor of safety for λ is 2 to 3 Here γ is 110 cft Vfa Case 1, Considering Compression Force, Down Case 2, Considering Tension Force, Upward

Developed shear at tower / pole / guy leg. Case 1 Case 2 Factor of safety SF (Min 1.5 by TIA 222F code) Factor of safety SF (Min 1.5 by TIA 222F code) H.

=

Downward P Upward P Footing Weight Footing Length B Footing Depth V Vfa, case 1 Vfa, case 2 SF (Case 1) SF (Case 2)

= = =

(HR) (Mov)

= =

(Mres) SF

= =

OVERTURNING MOMENT 1 Resultan horizontal load 2 Moment overturning 3 Moment resisting 4 Factor of safety SF (Min 1.5 by TIA 222F code)

= = = = =

167.70 -138.81 17.74 13.94 9.68 10.79 117.20 45.68 = =

kip kip kip ft ft kip kip kip

Page 278, Donald P. Coduto Foundation Design, Pprinciples and Practices

< <

V V

ok ok

<

1128.92 kN

10.86 4.23

66.63 kN 223.20 kN 1128.92 kN 5.06 >

1.50

ok

Below parts havent yet been checked. I.

DESIGN OF PAD 1 Concrete cover 2 Material Grade Concrete K-175 Steel Reinforcing Bar (U-39) 3 Bending Moment Pad cantilever length Compression Soil pressure at the perpendicular side of chimney

(d')

=

(fc') (fy)

= =

20.68 MPa 413 MPa

(lc)

=

1.825 m

Maximum

(σc)max

=

2 67.59 kN/m

Minimum

(σc)min

=

2 43.36 kN/m

(Mu)

=

99.11 kNm

(σup)

=

2 -34.18 kN/m

(Mu)

=

-56.93 kNm

Ultimate bending moment Uplift Soil pressure at the perpendicular side of chimney Design uplift pressure Ultimate bending moment 4 Reinforced concrete design for bending

ρmin ρmax ρmax β φ

=

70 mm 3.00 ksi 59.90 ksi

for 1 m' span

for 1 m' span

0.00366

=

0.75*ρb

=

0.01607

=

0.85

=

0.8

=

-71.16 kN

db

=

= = = =

1000 mm 430 mm -0.38 -0.0024 2 -1042.35 mm

As1

=

Upper pad Mn Design width Effective depth Rn Required area ratio of bar

(Mu/φ) (b) (d) Rn=Mn/bd2

(ρreq) (Asreq)

Required area of bar Spacing s=As1/Asreqxb Lower pad Mn Design width Effective depth Rn Required area ratio of bar Required area of bar Spacing s=As1/Asreqxb

(Mu/φ) (b) (d) Rn=Mn/bd2

(ρreq) (Asreq) nos

= =

Use D

16

=

123.89 kN

db

=

= = = =

1000 mm 430 mm 0.67 0.0042 2 1814.75 mm

As1

=

= = =

Development length Minimun development length

195993455.xls.ms_office

-192.89 mm

110.79 mm 30.22 =

12/16/2013

Use Use D Use

16 mm 2 201.06 mm

-

136 16 mm

2 201.06 mm

0.004220356 16 22

-

136

300 mm

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Foot Plate

Basic Minimum Available development length ldb

0.5

0.02.As.fy/(fc') 0.06.db.fy

5 Concrete Bearing Capacity A1

=

A2 Max load on the center of cap, (Fc)ver+W ch

= =

Concrete Bearing Capacity f.0.85.fc'(ab.A1) 6 Checking of one-way shear along Section A-A (eff. Face chimney) Strength reduction factor (f) Compression (bw) Web width Effective depth (d) Factored shear force (Vu) (Vc)

Vc =

1 6

f c' b w d

Uplift Factored shear force

=

= =

365 mm 11 mm

=

430 mm

0.36 m

2 2

18.0625 m 766.72 kN #REF!

kN

=

0.65

= = = =

4250.00 430.00 79.25 1024.596

#REF!

ab

=

2

f

=

0.7

(Fc)ver+W ch

#REF!

mm mm kN kN

(fVc)

=

665.987 kN

>

Vu

...OK

(Vu) (fVc)

= =

-62.473 kN 665.987 kN

>

Vu

...OK

7 Checking of Punching Shear

bc

=

as Compression Chimney width Effective depth Perimeter length (bo)=4.(bc+d)

(f)

1

=

=

(bc) (d) (bo)

= = =

Factored shear force Vu=(σc)(B2-(bc+d)2) (Vu) Concrete shear strength (Vc) is the smallest amount of :

=

1149.19 kN

=

4028.20 kN

=

2744.13 kN (Vc)min

=

2685.47 kN

(fVc)

=

1745.55 kN

æ 4 ö ç2 + ÷ Vc = ç b c ÷ø è

f c' bo

æa d ö Vc = çç s + 2 ÷÷ è bo ø

f c' bo

Vc = 4

d 12

f c' b o

d 12

d 12

Uplift Chimney width Effective depth Chimney concrete cover Perimeter length (bo)=4.(bc+d-2d') Factored shear force Vu=(σup)(bo2-(bc-2d)2)

0.65

20 (for corner colomn) 0.6 m 0.43 m 4.12 m

=

2685.47 kN

(fVc)

=

1745.55 kN

(bc) (d) (d') (bo)

= = = =

0.6 0.43 0.07 3.56

(Vu)

=

-430.93 kN

>

(Vu)

...OK

m m m m

Concrete shear strength (Vc) is the smallest amount of : æ 4 ö Vc = ç ç2 + b ÷ ÷ c ø è

f c' bo

æa d ö Vc = çç s + 2 ÷÷ è bo ø

f c' bo

Vc = 4

d 12

f c' b o

d 12

d 12

(fVc)

195993455.xls.ms_office

=

#REF!

kN

=

#REF!

kN (Vc)min

=

#REF!

kN

(fVc)

=

#REF!

kN

#REF!

(Vu)

=

#REF!

kN

=

#REF!

kN

12/16/2013

#REF!

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Foot Plate

J.

DESIGN OF CHIMNEY 1 Material Grades Concrete K225 Steel reinforcement bar 2 Slenderness Evaluation bc lu

(fc') (fy)

= =

= =

0.6 m 2.85 m = =

I For a braced frame klu/r 3 Axial and Moment Forces Compression Ru' Pu' Mu' Uplift Ru Pu Mu 4 Longitudinal Bar Design

rmin = rmax =

k = r = 4 0.0108 m 16.454 <

= = =

66.63 kN 745.95 kN 189.88 kN.m

= = =

68.05 kN -617.46 kN 193.96 kN.m

0.0034 0.0145

According to Column interaction chart, available rebar Number of rebar Diameter of rebar

= =

20 nos 16 mm

rmin Development length Minimum development length 90 degrees standar hook Available development length

18.63 MPa 413 MPa

8db

= = =

5 Stirrup Design Steel U-24

fy

=

f =

0.85

=

0.8

Asreq

=

= 128 mm 259 mm 1825 mm

or >

128 mm

=

Av

=

>

(fVs)

f bw d

(fVc)

=

604.185 kN

Maximum shear load for stirrup

(fVs)max

=

2134.788 kN

smax

=

250 mm

Use D 10 >

OK

155 mm

db

(fVc)+(fVs) K.

rmax

0.0112 <

240 MPa

66.626 kN 133.204 kN

Maximum spacing

2 0.000201062 m

0.65

= =

' c

2

...OK

=

(Vu) (fVs)

1 Vc = 6

0.36 m

= 34

b f

r

<

1 0.173 m A

(Vu)

OK

10 mm 2 0.000157 m

OK -

150

OK

Sloof Steel U-39

Ps = (60%P) fy bs

= = =

447.570 kN 413 MPa 0.3 m

hs

=

0.5 m

Depth of sloof

hsl

=

0.3 m

Minimum base width of tower

Bb

=

7 m 664.309 kN

nos dbs

= =

>

447.570 kN

8 16

OK

Stirrup Design

Maximum spacing

195993455.xls.ms_office

fy

=

240 MPa

db

=

f

=

0.65

Av

=

=

250 mm

smax

12/16/2013

Use D 10

10 mm 2 0.000157 m -

200

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Foot Plate

L.

ESTIMATED VOLUME OF MATERIALS 1 Volume of concrete K-225 2 Weight of steel bar Pad Lower Upper 3 Chimney Longitudinal bar Stirrup 4 Sloof

One leg

3

Use Use

22 22

D D

16 16

1.58 kg/m 1.58 kg/m

= =

Use Use

20

D D

16 10 -150

1.58 kg/m 0.62 kg/m

= =

Use Use

8

D D

16 10 -200

1.58 kg/m 0.62 kg/m

= =

Total

=

5 Total 4 (four) leg of lattice tower Volume of concrete K-175 Weight of steel bar

= =

6 Excavation soil volume One leg

(EVs)

=

One tower

(EVs)

=

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11.11 m

=

12/16/2013

3 44.43 m 2400.83 kg

3 11.59 m 3 46.37 m

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Foot Plate

XACTLY 30º per TIA 222F] [But this value… EXACTLY 16 kN/m3 per TIA 222F]

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Foot Plate

use this SF for RCC building design

ng, if compression passes

...OK ...OK

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Foot Plate

nciples and Practices

nciples and Practices

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Foot Plate

172.76 kg 172.76 kg 90.06 kg 20.15 kg 88.48 kg 56.00 kg 600.21 kg

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