IS 802

Indian Standard CODE OF PRACTICE FOR USE OF STRUCTURAL STEEL IN OVERHEAD TRANSMISSION LINE TOWERS

( Second Revision ) 0.1 This Indian Standard

(Second Revision) Standards Institution on 11 July 1977, after Structural Engineering Sectional Committee Structural and Metals Division Council and Council.

was adopted by the Indian the draft finalized by the had been approved by the Civil Engineering Division

0.2 This standaxd has been prepared with a view to establishing uniform practice for design, fabrication, testing and inspection of overhead steel transmission line towers. This part covers requirements in regard to material, loads and permissible stresses. Provisions for fabrication, galvanizing, inspection and packing will be covered in Part II whereas testing of these towers will be covered in Part III of this standard. 0.3 This standard was first published in 1967 and was revised in 1973. he following important modifications have been made in this revision: a) Clause 7 relating to types of towers has been modified keeping in view the practices being followed in the country and abroad. b) Clause 8 relating to the 'broken wire conditions' have been further elaborated both for single circuit and double circuit towers. c) A table giving the values of allowable unit stresses for different

.!:... ratios of compression members, as stipulated in 10.1, has been r added. d) Appendix A giving typical calculation of tower loading has been revised. Method of calculation of wind loads on tower body has been improved upon. e) Numerical values of loads and stresses and formulae for calculating permissible stresses, etc, have been given both in SI and metric units. It is proposed to change over to SI units completely in the near future.

0.4 As transmission line towers are comparatively light structures and alII SCOPE . ' . t be adopted that the maximum wind pressure is the chief criterion for their design, tl' h' t ndard stipulates the various deSIgn conf,lderatl~ns dOtransmission Sectional Committee felt that concurrence of earthquake and maximu11.1 T IS~ a of self-supporting steel lattice towers or ~v~~ ea t sses wind pressure is unlikely to take place. Specific provisions of earthqual in the d~lgnvers loads combination of loads and permIssl Ie s re ... forces have, therefore, not been specified in the standard. However, i1ines an co ,. .' f alvanizing inspection, packmg and particular regions where earthquakes are experienced frequently, eart!, 1.1.1 Details r~g.ardlI:g fabnca lOn, ~eing cover~d in Part II and Pal't III q uake ~orces may be c.onsidered in the ~esign of steel transmission lintesting of transmIssl~n Ime towers are towers m accordance wIth IS : 1893-1970 . • of the code. ,, 'd 't h been assumed that the . , ,.. '£ I t' g the provlSlons of th,s co e, I as 8.5 In regard to desIgn of foundatlOn for transmISSlOn hne towers refereno NOTE - WhIle, ormu a: h bolts may be made to IS: 4091-1967t· structural connectiOnsare roug . d ers and special towers for river 0.6 Any details of design or other items not covered in this code ( includin! 1.2 This code does not cover w~l~~e covered by separate code, Part II and Part III) shall generally be in accordance with IS: 800-1962l crossing or other long spans. e .

TtU~~

0.7 The code envisages for the present, fabrication of transmission linl RIAL towers by. means of bolted connections o.nly. The provisions of this codl2. MATE " rms shall be of structural steel relate mamly to structural steel conformmg to IS: 226-1975§ and Gra

w here - r

These formulae are applicable provided the largest ratio bit is not more than the limiting value given by:

(!!-)

)2

KL

yield stress of the material,

length of the compression

E = modulus

. --=-

guaranteed

20 000 000 kgf/cm2 KrL

= (

or Fa

= allowable unit stress in compression,

~

when F is in N/mm2 y

< yFy

1 000

-"-F-=V

l!.->

when

Fy

I

y

310

whcnFyisinN/mm2

V Fy

where

b T> y1 000 Fy

when Fy is in kgf/cm2

9.2.3.1 For steel conforming to IS: 226-1975* in 9.2.3 will reduce to the following: a) Fer

N/mm2

*Specificationfor structural steel (standard quality)

(fifth revision).

=

459 -

15'7(

2

is in kgf cm

+)

N/mml

Fer

f)

= 4 680 - 160 (

r

kgf/cm2

-'17800

b) Fer

=

(+

where 13

<

c) M

~

N/mm

.

b where -> 20 t

value of ~up

panel with values of

to and including

60

+ 0'50

L

r

r up

to at

!::.T

120 (curve 3

of Fig. 4) e) Member unrestrained against rotation at both ends of the unsupported panel for values of

PERMISSIBLE STRESS IN BOLTS

!::.. from 120 to 200 ( curve 4 of Fig. 4 ) r

N/mm' (kgf/cm'

1. Shear

-

f) Members partially restrained at one end of the unsupported

(2)

of

)

against rotation panel for values 28'6

!::.. ov~r 120 up to and including

+ 0'762

L ~r

225

r

Shear stress on gross area of bolts

For gross area of bolts see 14. For bolts in double shear tI area to be assumed shall I twice the area defined

( curve 5 of Fig. 4) g) Membe;; partially restrained agail!st rotation at both ends of the unsupported panel for 46'2 values of Lover

Bearing For

Bearing stress on gross diameter of bolts

3.

+ 0'75

r

9.3 Stress ~n Bolts - The estimated stresses in the bolts multi Ii d the appropnate factor of safety shall not exceed the value given in ~a~le~

2.

30

~

nd including 120 ( curve 2 of Fig. 4 ) d) ~embers with normal framing eccentricities both ends of the unsupported panel for

or

TABLE 3

bel' with concentric loading at one end edmnormal eccentricities at the other end of

the unsupported

(fY

r

Type of Members

tb < 20

2

590000

KL .--/ Value of~

the

bolt

area

in bearin

see 14.5

r

1201 up to and including

+ 0'615

L r

250

-

( curve 6 of Fig. 4).

10.1.1 A single bolt connection

Tension Axial tension stress on the root area of the thread of bolt

10. SLENDERNESS RATIOS 10.1 Compression Members - The slenderness members shall be determined as follows:

Type of Members a) L.eg s~ctions or joint members bolted at connectiOns m both faces ( curves 1 and 4 of Fig. 4 )

shall not be considered as offering restraint against rotation. A multiple-bolt connection properly detailed to minimize eccentricities shall be considered to offer partial restraint if connecti?n is made to a member having adequate flexural strength to resist rotatlO~ of the joint. Points of intermediate support shall not be considered . I as offermg restraint to rotation unless they meet the criteria outlined above. compress10 10.1.2 In the design of members, the length L shall be from centre to XL cent~e o.f intersection at each end of the member. Example showing the Value of applIcatiOn of the procedure contained in 10.1, 10.1.1 and 10.1.2 and f meth~ds o.f determining the slenderness ratios of leg and bracing members L are glVen m Appendix B. f

10.1.3 The limiting values of

"£.

shall be as follows:

T

b) Members with concentric loading at both ends of the unsupported to and including

panel with value of ~

120 ( curve 1 of Fig. 4 ) r

up

Leg members and lower members of the cross-arms III compression Other members carrying computed stresses Redundant members and those carrying nominal stresses

200 250

/' I

IS,: 802 (Part I) • 1977

----

. -.

/

TABLE.

ALLOWABLE U STRESS Fy

I Y

. ....

)

.

.

.

10.1.4 Table 4 gives for ready reference, 2

stresses in N /mm types as stipulated

.

,

.:

the values of aHo.wable wi

(kgf/ cm') for L ratios of compression members of th r in 10.1 for steel conforming to IS: 226-1975*.

10.2 Tension M••••ber - The ,]end"ne" "tio of a memb" ,any;"

axial tension only, shall not exceed 375.

255 (2 600)

as 11.1 follows: Minimum thickn", ofgalvanizedand painted tow" membe" ,hail ,

M£nimum Th£ckness, mm

r-----.A.._'-- __...., Other

255 (2600) 255 (2600)

11. MINIMUM THICKNESS

Leg members and lower members of cross-arms in compression

I

255 (2600)

Galvanized

members

*Specification for structural steel (standard quality) (fifth reVision).

Painted

255 (2600) 255 (2600) 255 (2600) 255 (2600) 254 (2590) 254 (2590)

-s4

254 (2 590

-87 (890) --

-76 (780)

-_. -6-168 ) (69 0 __(620) __(550) 60 54

254 (2 590

86 (880)

7~g). (6~b) ( -

254 (2590

"-as(870)

(7~6) --

(6~b).

254 (2590

-11-3 (850)

(7~6) --

253 (2580

-------a2

(7~6) --

(2 253 580

-8-1 (830)

(840)

253"-g() (2 580 (820). 253 - -7-9 (2580 (810) 252 -7-8 (2 570 (800) 252 - -~7-7-1 (2570 (790)

I

(610) --

(550) 53

49 (500) 48 (490) 48

(6g~)

(540) _(490) 53 47

(6~~) --5

(600) -5-8-

(540) 52

(6~0) --

(590) -5-7'

(530) ~~ 52 47

---

----s9'

71 6 ) (580) (730) (656 __. -57 (7~6) (6~6) (580)!~ -~' -~ 70 63 (570) (720) (640) __. --62 56 (77~) (630) (570) --68 (6~6) (560) (700)

-----s5

(480) 47

(530) (480) __ ~ 51 (480) 50 46 (510) (470) __ ~ 50 (510) (460) 49 45 (500) (460)

IS I 802 ( Part I ) • 1977 TABLE 4 ALLOWABLE UNIT STRESSES IN Njmm2 (kgffcm2

_

)

FOR MEASURED StENDERNESS RATIOS (Ljr) (Clause

,

J I

I

Curve 6, measured Llr

120

(KLfr",,46'2+ 0'615 Llr)

--- -

---

---

---

---

-

--- ---

---

--

:1

0

(KLlr=Llr) -+-

r .I-

0

13'3

26'7

60

40

80

---

---

40'0

53'5

20

30

3e1

40

50

66'7

---

,--

---

10

--

--

173

--

250

--

;rff: ' "212 ' •...225

186

-'

I

120

100

I

--

--

---

-'--

.~

--

-:

--

60

70

80'0

93'3

,.

.

---

---

80

100

90

120

106'7

,

'

..

--

~

--

---

110

120

110

120

130

10

20

I (2600) 255

254 (2590)

252 (2570)

254 (2 590)

2

255 (2 600)

254 (2590)

3

255 (2600)

4 5 6 7 8 9

247 I (2520)

------

40

50 -

234 242 •. (2390) (2470r

60

225 215 (23QO) . (2 190)

152 (1550)

212 (2 160)

199 (2030)

184 (1 880)

168 (1 720)

210 (2 140)

197 (2 dl0)

182 (1860)

166 (1 700)

232 223 213 (2370) , (2280) - (2 170)

254 (2590)

251 (2 560)

246 (2510}'

232 . 240 • 222 (2270) (24S0Y (2370r

255 (2600)

253 (2580)

250 (2550)

231 245 ' 239 / (2 500) (2440) (2360)

255 (2600)

253 (2580)

250 (2 550)

245 (2500)

255 (2600)

253 (2580)

249 (2540)

244 (2490(

255 (2600)

253 (2580)

249 (2 540)

237 243 , (2480)" (2 420)

254 (2590)

252 (2 570)

248 (2530)

243 (2480)

236 (2410r

227 (2320)

254 (2590)

252 (2570)

248 (2530)

242 (2470)

235 . 226 (2400) . (2310)

237 (2420)'

--

137 (1400)

156 (l 590)'

169 (I 730)

240 (2450)'

220 (2250)

173 (l 770)

185 (1 890)

246 (2510)

---'

---

209 (2 130)'

201

~

---

196

---

lRI (1 850)

130

---

200 (2 ~40)

251 (2560)

224 . 214 (2290) (2180)

221 (2260)

188 (1 920),

154 134 (1570) " (1 370)

233 (2 '380):

---

--

171 (1 75~)

241 (2460y'

---

203 (2070)

100

90

187 (1 910)

247 (2520)

230 238 (2430) . (2 350)

---

--'

251 (2 560)

II

80

70

150

140

--164

116 (1 180)

---

100 (1 020)

114 (1 160) ~,

99

131. (I 340)'

113 (1 150) ~

971'

151 (1 540)

129 (1 320)

111 (1 130)

149 (1 520)

127 (1 300)

109 (1110)'

147 (1 500)

125 (1 280)

108 (1 100)

93 (950)

123 (1 280)-

106 (1 080)

92 (940)

105 (1 070)

---

---

96 (980) 94 ~_

208 (2 120)

E (1 G(0)

163 145 179 (1830) " (1 660) . (1480)

228 , 219 (2330)" (2230)

207 (2110)

h13 (l 970)

162 178 (1 820)', (1650)

143 (1460)

121 (l 240)

217 (2210)

206 (2 100)

191 160 176 (1 1950) (1800) , (1630)

141 (l440)

103 120 I (1 220)- I (l 050) ~_

216 (2200)

204 (" 080)

190 174 (11940) , (I 780)

139 (1420)

---

194

.l

23 J

(I 680)

158 (I 610)

---

\

101. 118 I (1 200y , (1 030)·

--

~-

J.

91 (930)

I

89 88 (900)'

170

-170

160

-,-'

---

160

150

~

229, 220 (2 340r~ (2240)

'1

~.

--

--

--

76 (780)

87 (890)

--

68 (690)

--

3 -------

...

180

200

--

190

--

180

--61

190

---

--

75 (770) 74 (760)

67 (680)·

59 (600)

53 (540)

73 R3 (750) (850) 82-7-2-65' (840) (740) -8-I-------:n-

66 (670)

59 (600)

53 (540)

86 (880) 85 (870)

(830) (730) ------SO--7-1(820)

(730)

(810)

(720)

(660) ~ (650)

54 (550)

---58 (590)

52 (530)

-5-7-152 (580) (530)

~

---;;g---m

57 51 (580) (520) 63 -5-6-150 (570) (510) (640) ---6-256 50 (630) (570) ~

I

(650)

78 691

---I (800)

(710)

77 I 68 (790) (700)

61 (620)

55 (560)

200

--49

54 (550)

67 (680)

60 (610)

--

--

(620)

--

,:

'.'

~ '~"

--

0

255 (2600)

I

-

159

---

--,--

234

218

./ ,-'

Curve 1 and 4 measured Llr./

KL

146

133

--20

--0

( KLlr=30+ 0'75 Llr)

r

---

--

---

--

Curve 2, measured Llr

OF-

--

201

1

0

( KLlr=60+ 0'5 Llr)

1

185

--"~~'"

120

~e 3, measured Llr

169

'-

Curve 5, measured Llr

(KL/r=28'6+ 0'762 Llr)

153 I

136

---

--

255 NjmmJ (2600 kgfjcm2)

10.1.4)

'~ : !

=

FOR STEEL WITH YIELD STRESS Fy

49 (500)

(500)

48 (490) 48 (490)

--'

47 (480)

--

47 (480) 47 (480) 47 (480) 46 (470) 45 (460) 45 (460)

·2. NET SECTIONAL AREA 1 Th t sectional area shall be the least area which is to' be obtained ,2. d d et~eg from the gross sectional. area, the area of all holes cut by any )y , ehtue .1'Inagonal or zigzag I' "th me across t I1e mem bId er. n etermmmg e 1 ,tra1 g , 0f the holes to be dedncted from ·gross sectional area, the full 1 ,ota ar '1 . f the first hole shall be counte d , p Ius a r.!ractlOna part x, 0f each ~~~e~ding hole cut by the line of holes under consideration. The value )f x shall be determined from the formula,

pz ' x

=

I -

4 gd

where p,= longitudinal spacing (stagger), that is the distance between two successive holes in the line of holes under consideration; ,bl';; transv6rse' sihc~J;ig (gaukc' ),"that is the distance between .'.~the S'ame tWo consecutive holeS as for P; and

'I

I

d ,= qliameter of holes.

For holes in opposite legs of angles, the value of g should be the sum f the gauges from the back of the angle less the thickness of the angle,

13.1 In t~e case, of single angles in tension tonnected net effectlVe sectIon of the angle shall be. taken as A

by one leg only, the

+ Bk

where A = net sectional area of the connected leg, B = area of the outstanding leg = (l - t) t, l = length of the outstanding leg~ t = thicklJess of the leg, and I k=. I

+ O'35~ A

13.2 In the ca f ' f )nly on I s~ 0 pall' 0 angles back to back in tension connected by Uea sha~l begtOk each angle to the same side of gusset, the net effective e a en as

~+ '25

Bk

IS : 802 ( Part I ) - 1977

APPENDIX where

A

(Clause 0.3) A B k

=

net sectional area of the connected leg,

WER LOADINGS FOR FTDOOUBLECIRCUIT LINE '~LCULATION ( ~ 132 k

= area of the outstanding leg, and 1

=

B' 1

A-I. BASIC DATA a) Type of tower

+ 0'2'11

13.2.1 The angles shall be connectecl together along their lengths accordance with the requirements of28.4 and 29.2 ofIS: 800-1962*.

14.1 Minimum Diameter be less than 12 mm.

of Bolts -

The diameter

A TYPICAL

°v

of bolts shall n

Tangent tower with suspension 0 string ( 00 to 2 ) 335 m

b) Normal span 2 1910 N/mm2 (195 kgf/m ) c) Wind press(u~r be taken on It 1) Tower 0 f one times the exposed area 0 2 face) d d wire 440 N /m2 ( 45 kgf/m ) 2) Conductors an groufnll pro(To be taken on u jected area) UCTOR

14.2 Preferred Sizes or Bolts - Bolts used for the erection of tranA_2. CHARACTERI~TICS ~F ~_~~~* mission line towers shall be of diameters 12, 16 and 20 mm. a) Size conformmg to IS . 39

30/3'00 mm Al St ACSR

+

7/3'00 mm

. . f the 21 mm b) Overall d 1 a met e r 0 conductor 261'2 mm2 ) Area of the complete conductor n9 500 N ( 9 127 kgf) 14.4 Gross Area of Bolt - For purposes of calculating the shear stro ~) Ultimate tensile strengtl;1 9 570 N/km ( 976 kgf/km) the gross area of bolts shall be taken as the nominal area of the bolt. e) Weight ... 37 250 N ( 3 800 kgf) (say) f) Maximum workmg tenslOn 14.5 The bolt area for bearing shall be taken as d X t where d is th S OF GROUND WIRE diameter of bolt, and t the thickness of the thinner of the parts joined. A-3. ·CHARACTERISTIC. t 7/3'15 mm galvanized strande~ a) Size con fo l' m 1 n g 0 steel wire of 110 kgf/mm 14.6 The net area of a bolt in tension shall be taken as the area at the roo IS: 2141-l968t quality of the thread. 9'45 mm b) Diameter . 54'5 mm! 14.7 Holes for Bolting - The diameter of the hole drilled or punch~ c) Area ofcomp~ete ground wue 56000 N (5710 kgf) shall not be more than the nominal diameter of the bolt plus 1'5 mm. d) Ultimate tensl1e strength 4200 N/km ( 428 kgf/km) e) Weight . . 24 500 N (2 500 kgf) (say) f) Maximum workmg tensIOn. ' thod of calculation A-4. TOWER LOADING - Table 5 glveS typIcal me 15.1 The angle between any two members common to a joint of a trusse/ of tower loading, , se of normal 'd' h I ding' on tower m ca frame shall preferably be greater than 200 and never less than 150, due tl A-4.1 Figures 5, 6 an d 7 m Icate t e oa ~ d t r conditions respecuncertainty of stress distribution between two closely spaced members. conditions, broken-wire conditions and broken-Wcan uc 0 'nd loads acting as '1 "V W W W W W Wand 7' are WI 6) tlve y. YI g, 1, ~' 3'. 4' 5'. 6 d lculation in Table . shown at the respectIve pomts ( see wmd loa ca d 14.3 The length of bolts shall be such that the threaded lie in the plane of contact of members.

portion does n(

-------, . d ted • Specification for hard drawn stranded alumml\~m an s tors for overhead power transmission purposes ( revls~d). t Specification for galvanized stay strand (first revISIon).

cored

aluminium

con uc-

TABLE 5 TOWER LOADINGS ( Clause A-4 ) SL

DESCRIPTION

No.

IN 51 UNITS

,..----

Normal

-J,.._.

Condition

.....•

Broken Wire Condition

IN METRIC UNITS

,..-------------"'------------. Normal Condition

Broken Wire Condition

(I) i) Ground Wire Support a) Transverse loads 1) Wind load on wire 2) Due to deviation

335* X 0'00945. X 440 = 1392 N 2 X 24500 X Sin-1° = 854 N

0-6tx

1392 = 835 N

= 427

0-5 X 854

N

Total

0-6t X 142'2 =85'3 kgf 0'5x87'1 = 43'6 kgf

229-3 ~gf

b) Vertical loads I) Weight of wire per weight span 2) Weight of ground wire attachment 3) Weight of lineman with tools

(335 X 1-5 )t X 4'20 = 2110 N

0-6 X 2110 = 1265 N

50 N

50 N

(335 X 1-5)t X 0'428 = 215-0 kgf 5-0 kgf

0'6 X 215'0 = 129'0 kgf 5-0 kgf

1500 N

150'0 kgf

Total

2815 N

c) Longitudinal ii)

335* X 0-00945 X 45 =142'2 kgf i 2 X 2 500 X Sin 10 , . = 87-1 kgf

284-0 kgf

24500 N

2500

kgf

Power Conductor Support a) Transverse load I) Wind load on conductor 2) Wind load on insula tor sprip.g. Diameter of insulator skirt = 254 mm. L~~gth ::;f insulatot' string with arching horns = 2000 mm.

=

335 X 0-021 X 440 = 3 100 N

0-6 X 3100

1910 X 0'254 =485

1910 X 0'254

= 485

N

Net effective projected area 0'5 X 2000 X 254 1000xI000 = 0-254 m" 3) Due to deviation 2 X Sin 10 X 37250 = I 305 N

1860 N

N

0-5 X Sin 10 X 37250 =325 N

335 X 0-021 X 45 = 316'5 kgf

0'6 X 316':> = 190'0 kg[

195 X 0'254 = 49'5 kgf

195 X 0'254

2 X Sin lOx 3 800, = 133'0 kgf

0'5 X Sin lOx 3 = 33'3

= 49'5 kgf

499'0 kgf b) Vertical Load 1) Weight of conductor per weight span 2) Weight of one insulator string including hardware 3) Weight of lineman with tools

335 X 1-5 X 9'57 = 4800 N 600 N

0-6 X 4800

= 2 880

6900 N Nil

r

Distance between conductor point of I sion and the centre ~ the structure =4'0 I (say) I Width of the tower L ductor level = 1'4

I

600 N

335 X 1-5 X 0'976 = 490'0 kgf 60'0 kgf

4980 N

700'0 kgf

0'5 X 37 250-18625 18625 X 4-0 2 X 1'4

iii) Torsio7Wl Shear per Face at the Top Conductor Position

=

N

N

26610 N

Nil

272'8 kgf

0'6 X 490

=

294'0 kgf 60'0 kgf

504'0 kgf

0'5

X

3 800 -1 900 kg£

1900 X 4'0=2 2 X 1'4

714 k f g

e 1 suspen- \}line of metres at conm (say)

iv) Wind Loads on Towers -

I)

I I

J

The details in regard to the method of calculating equivalent wind loads at ground and conductor points due to wind load on tower are given in Table 6.

v) Dead Weight if Structure - Dead weight of the structure up to the point where stresses are being computed *Vv'ind span = Normal span _ 335 m. tIt is assumed that spans are equal. :::Weight span = 1'5 X Normal span = 1'5 X 335 m.

= Ws

( Clause A-4.1 )

ALT!TUDES

m

GROUND LEVEL

I

W~

WIRE

EXPOSED AREA OF THE MEMBERS OF THE PART NORMAL TO THE DIRECTION OF THE WIND ( TRANSVERSE FACE) (m2)

1

2

4'50

1'40

I

C.G. OF THE GEOMETRICAL CONFIGURATION OF THE PART WITH RESPECT TO BOTTOM OF THE PART (AsSUMED) m

AREA M MENT AT BASE OF PART (n -.m)

3

4

1"43

2'0

.

To Top of Part (4)-;-(1)

To Base of Part (2)-(5)

5

6

0'444

W,

TOP CONDUCTOR LEVEL

PART I

~

PART II

W2 ~

MlDDLE CONDUCTOR LEVEL

PART III

N [(7)Xl'5X 1910*]

kgf [(7) X 1'5x 195*]

7

8

9

0'444

1270

130

1'867

5350

545

2'214

6340

646

2'645

7580

774

3'35

9600

980

3'82

10940

1115

4'23

12120

1238

2'35

6740

687

0'956

. 0'911

4'1

-

2'30

4'50

Total (5)+(6)

2'06

-

1'159 -

1'055

4'74 1'245 1'40

PART IV

3'06

7'0

3'20

--_.

W,

BR ACING LEVEL

1'98

-----

f w) I'>., ',.<

BOTTOM CONDUCTOR LEVEL

2'07

4'50

WIND ON POINTS

AREA TRANSFERRED (m2)

PARr V

9'8

-

HI

3'58

I

3'30

---

1'66

-1'69

1'8

I

BRACING LEVEL

Ws

-

PARr VI

7'()

-

-

'--3-9G

-

1'89

1'93 3'40

3'5

, GROUND LEVEL

CONCRETE LEVEL

W&

'tV,

;Qm

rLl"\ ! ~

2'03

--I--2'2 PAR' VII

6'00

4'55

2'9

3'2 2'35

of TOW'R *Wind on tower body is ata rate of 1910N/m2( NOTE -

Overhanging

flanges on the transverse

19 kgf/m2). face ~fthe tower shall not be considered

for working

out the wind load on tower.

....,

:;-

l> ,j>.

-.J



~

5' 0.

0'> -.J ,j>.

0" \lJ

0

0.

-

"" ""0

0

""

,j>.