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Transmission Tower Design with

respect to Civil Engineering

Project Done By :

Nisarg B TrivediSandeep R Patel

Dharmendrgiri S Goswamee

GROUP CO-ORDINATOR NAME : Prof Y.S.Patelsir

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Overview Of Previous Work:

Tower Typesand Shapes

Self-SupportingTowers

ConventionalGuyed Towers

Chainette GuyedTowers

Vertical /barrel

typeHorizontal /Wasp

Waist

Delta/Cat Head

H-Structure Type

TowerGeometry

Peak

Cage

Cross arm

Boom

Tower Body

Body Extension

Leg ExtensionStub/ Anchor

Bolts and BasePlate Assembly

Fundamentalof Surveying

Reconnaissanceand routealignment

survey

Detailedsurvey

Tower spotting

Check survey

ElectricalClearances

Minimum groundclearances.

Minimumclearances above

river/lakes.Air clearances.

Clearancesbetween conductor

& ground wire.

Clearances atpower line crossing.

Power line crossingrailway tracks.

Power line crossingcommunication line.

Power line runningalone or across the

road.

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Present Work Analysis:

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Requirements Of Loads On

Transmission Lines

i. Climatic loads related to reliability requirements: Wind load (Non- Snowy regions)

Wind load (Snowy regions)

Wind load without Ice (Non- Snowy regions)

ii. Failure loads related to security requirements:

Unbalanced Longitudinal loads & torsion loads due to broken

wire

Anti-cascading loads

iii. Construction and maintenance loads related to

safety requirements: Loads during construction

Loads during maintenance

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Nature of loads on towerTransverse loads (TS):

Wind load on tower structure, conductor, ground-wireand insulator strings. Component of mechanical

tension of conductor and ground-wire.

Vertical loads (VS): Load due to weight of each conductor or ground-wire

based on weight span and weight of insulator strings.

Self weight of tower including in vertical load.

Longitudinal loads (LS): Unbalanced Horizontal Loads in Longitudinal

Direction due to mechanical tension of conductor

and/or ground-wire during broken-wire condition

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Transverse Loads (TS)

Wind load on conductor/Ground-wire

Fwc = Pd x L x d x Gc x CdcWhere,

Fwc = Wind Load In Newton

Pd = Design Wind Pressure In N/M

L = Wind span in meters

d = Diameter Of Conductor/Ground-wire In Meters

Cdc = Drag Coefficient Which Is 1.0 ForConductor And 1.2 For Ground-wire

Gc = Gust Response Factor Which Takes

Into Account The Turbulance Of The

Wind

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Transverse Loads (TS)

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Transverse Loads (TS)

Wind load on tower

Fwt = Pd x Cdt x Ae x GT

Where

Fwt = Wind load in Newton.

Pd = Design wind pressure in N/mm.

Cdt = Drag Co-efficient to wind blowingagainst any face of the tower.

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Transverse Loads (TS)

Ae = total net surface area of legs and

bracings including x-arm members.

GT =Gust response factor depending

upon terrain category and height of

CG panel above ground level.

Mechanical Tension of conductor and

ground-wire due to wind (Deviation load)

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Transverse Loads (TS)

This load acts on the tower as component

of Mechanical Tension of Conductor and

Ground-wire

Fwd = 2 x T x sin /2

Where

Fwd = Load in Newton.

T = Maximum tension of conductor

and Ground-wire at every day

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Transverse Loads (TS)

temperature and 100% of full wind

pressure.

= Angle of deviation

Total Transverse Loads (T) Under

Reliability Condition

TS = Fwc + Fwt + Fwd

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Vertical Load (VS)

weight of each conductor

Vc = A x Lx D

where,

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Vertical Load (VS)

Vc = total weight of conductor,

A = area of conductor,

L = length of conductor,D = density of conductor,

weight of tower

Vt = A x Lx D where,

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Vertical Load (VS)

Vc = total weight of tower,

A = area of each panel,

L = length of each panel,D = density of each panel

Total Vertical Load (VS)

VS = Vc + Vt

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Longitudinal load (LS)

The longitudinal load corresponding to

50% of the mechanical tension of

conductor and 100% of mechanical

tension of ground-wire shall be undereveryday temperature and full wind

pressure.

Longitudinal load of conductor

LS = (Fwd/2)

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Total load on Tower

Lt = TS + VS +LS

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THANK YOU FOR YOUR

ATTENTION