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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