Transmission Monopole

MONOPOLES FORMONOPOLES FOR TRANSMISSION & DISTRIBUTION

TRANSRAIL LIGHTING LTDTRANSRAIL LIGHTING LTDGammon Group

Office:Boomrang,A-201/209Boo ang, 20 /209Chandivali farm road,

Near chandivali studio,Andheri East,Mumbai 400072

M h h I diMaharashtra, IndiaTel: +91 (22) 40889696Fax: +91(22) 40889666

Email: [email protected]@URL: www.transraillighting.com

Manufacturing Divn:Survey No 227/1 Khanvel kherdi rd;Survey No. 227/1 ,Khanvel kherdi rd;Silvassa -396230 (U.T. Of D & N.H)` `

INTRODUCTIONNowadays most of the transmission utilities are facing problems in laying

the transmission lines in urban areas due to severe Right of Way problems.

This is in view of non availability of adequate land for installation of

conventional lattice type towers.

To overcome these practical difficulties, new concept of

I b i d ld idIs being used world wide

MAJOR PRJECTS & CLIENTSMAJOR PRJECTS & CLIENTS

USE OF MONOPOLES IN TRANSMISSION & DISTRIBUTION

Transmission Monopoles are Pole Structure used as replacement of Lattice

Type Towers This structure helps countering the constraints as Right of Way orType Towers. This structure helps countering the constraints as Right of Way or

Corridor width. Also for hilly terrains, a Monopole can be conveniently used

against a Lattice Tower. The Monopoles adds to the aesthetics of the city too.

The Transmission line using a Monopole can be accommodated on Highway

Curbs.

These Monopole based lines can give handy solutions to ROW based

problems, few of them are mentioned below:

Up gradation of line within the existing Corridor can be done using the

Transmission line Monopole.

These Monopole based lines can be constructed to feed Power to newindustry from existing sub-stations, both situated in city areas, where the

bl f i ht f iproblem of right of way is severe.

Relocate lines to take care of new railways / metros etc. In almost allmetro cities, major work on new trains / Flyover is going on and the existinglines are required to be diverted. Use of Monopole towers can take care ofsuch requirements.

These Monopoles can be used where the Transmission Line is ParallelThese Monopoles can be used, where the Transmission Line is Parallelto road.

These Monopoles can be used, where the Transmission Line is Passingthrough thick forest area, thus minimize the loss to environment.

Above are just few cases where Monopole installation can be the solution. j p

DESIGN METHODOLOGY

Approach to the Design of Transmission line is Similar to the Lattice type

structure Load Calculation & Line Clearance etc is carried in accordance withstructure. Load Calculation & Line Clearance etc. is carried in accordance with

the Standards / as per the Customer Specification.

REFERENCE STANDARDS

IS -875 (Part-III) 1987 : Code for Wind Loads on Structure.IS-802 (Part1/sec1) 1995 : Code for Transmission Line tower ( Material

Loads & Permissible stresses.IS-5613 -1985 : Code for design & Maintenance of Overhead

Power LinesPower Lines.ASCE 48-05 : Code for Design of Tubular pole for

Transmission Line.

INPUT DATA :

For Transmission Monopole Design input data is the forces i.e.

Transverse load – Load on EW & Conductor due to the wind pressure & component

of Mechanical tension due to line angle deviation.

Longitudinal load – Unbalanced force due to broken wire condition/ Stringing.

Vertical Load Dead weight of EW Conductor & other AccessoriesVertical Load – Dead weight of EW, Conductor & other Accessories.

All these values varies with respect to the following parametersg

1. Type of line & Deviation angle.

2. Properties of Conductor / Ground wire.

3. Normal Span

4. Wind Pressure Or wind zone.

5. Specific height requirement / Terrain.

STEPS INVOLED FOR DESIGN OF TRANSMISSION MONOPOLE

Step-1 - Decide the Geometry of the Structure & Its Approximate Height.

STEPS INVOLED FOR DESIGN OF TRANSMISSION MONOPOLE

Step-2 - Wind Pressure Calculation.

Step-3 - Sag Tension Calculation sag

Pr cal

Step-4 - Prepare Line Clearance Diagram diagram

Step-5 - Load Calculations ( For Reliability, Security & safety Condition)

Step-6 - Analysis of Monopole structure. Analysis

Load Calc

DIFFERENT PROFILES OF TUBULAR MONOPOLES DIFFERENT PROFILES OF TUBULAR MONOPOLES

DIFFERENT PROFILES OF TUBULAR MONOPOLES

BASIS OF DESIGN:Approach to the calculation is based on the Elastic Limit Principles, Where

load effects are compared with ultimate resistance of the structure.

BASIS OF DESIGN:

In Elastic limit state, strength or Capacity of the pole is assessed by moment

of resistance at Elastic Limit & the dimensions are decided. The maximum

bending stresses arising out of the calculated bending moments are

i t i d b l th i ld t f P lmaintained below the yield stress of Pole.

Stability & Stress analysis should be carried for each structural element.

Consideration should be Given to the Load effect Resulting out of deflectedConsideration should be Given to the Load effect Resulting out of deflected

shape of Structure.

Finite element Model of the Structure shall be developed & Entire pole structure

shall be Generated. Member in the deflected shape shall be adequately

represented and the point of maximum Stress is adequately defined.

ANALYSIS :ANALYSIS : Analysis of structure is carried using Power line software PLS-Pole. This

software allows generating the finite element model of the Monopole by

selecting the component & assembling them in to the finished structure.

I f Li & li A l i Wi h h li i dIt can perform Linear & non linear Analysis. With the linear option secondary

effect of structure displacement (i.e. P-Delta effect) is ignored, whereas in Non

linear analysis P-Delta effect is considered.linear analysis P Delta effect is considered.

PLS POLE can be run in two modes, Design Check Mode or allowable spang p

Mode.

MANUFACTURING UNIT

MAXIMUM USAGE FOR EACH LOAD CASE FOR EACH ELEMENT TYPE

DESIGN CHECKDESIGN CHECK• PLS -POLE can be run in two modes, Design Check Mode or allowable span

Mode.

STRENGTH CHECK:PLS-POLE checks the section strength as per following standards.

ASCE /SEIASCE /SEITIA / EIA -222FANSI / TIA 222-G

Design checksFor each design load case, the analysis produces axial, bending, shear, and

torsional stresses at the ends of each tubular element or at every Nodal

point. Then Combine effect of these Stresses is Checked with the allowable

stresses at that particular section Utility shall be less than 100%stresses at that particular section. Utility shall be less than 100%.

ASCE STRENGTH CHECKFor transmission poles designed according to ASCE/ SEI Standard 48-05

(ASCE, 2006) the strength usage is calculated at each of the Nodal points as:

SQRT { (fa + fb )2 + 3 (fv + ft )2 } / ( fall x S.F.)

Where: fa =normal stress due to axial load

fb l t d t b difb =normal stress due to bending

fv =shear stress due to shear force

ft =shear stress due to torsionft =shear stress due to torsion

fall =allowable (permitted) combined stress defined in ASCE

Standard 48-05. It is based on w/t (multiple flats). To calculate the unsupported( p ) pp

flat width "w", it is assumed that a steel plate bending radius of 4 times the

plate thickness is used. For a corner point, w/t is the largest of the values for

the two adjacent flat faces.

S.F. = Strength Factor for steel poles

Combine Allowable Bending & Axial Stresses for Polygonal Tubular Steel Pole

Structures are as follows.Structures are as follows.

For 16 Sided 565< √ Fy *w/t <958 for Fy Mpa

Fb= 0.852*Fy*(1.0-0.000522 √Fy *w/t) Mpay ( y ) p


Fb= 0.870*Fy*(1.0-0.000491 √Fy *w/t) Mpa


Fb= 0.852*Fy*(1.0-0.000434 √Fy *w/t) Mpa

Where,

Fy – Yield Strength

Fb – Allowable Combine bending & Axial Stress.

t – Wall Thickness

w – Actual Flat side dimension but not less than dimension calculated using bend

radius equal to 4t.

FEATURES OF PLS POLEFEATURES OF PLS_POLE

Performs Non linear Analysis.Generates Finite Element Model.Inbuilt codal provision for strength check.It has link with the PLS CADD (Wherein it can check for Allowable Span Mode)Pls_pole provides an user friendly interface.One can easily design the complex structures profiles i.e. H-frame , Y-frame ,A-frame etc.It l h k d fl ti i t tIt also check deflection in structure.It shows the W/T ratio for material strength check.Internationally accepted software for design and analysis and design.A l i d d i f ll t f M l T i i & Di t ib tiAnalysis and design of all types of Monopoles – Transmission & Distribution Monopoles, Guyed Monopoles, Communication Monopoles etc.

CONSTRUCTION OF MONOPOLE

Monopoles are Tubular Structures with the uniform Taper throughout the

Length It shall have polygonal cross section (i e 8 sided 12sided 16sided)Length. It shall have polygonal cross section (i.e. 8 sided, 12sided, 16sided)

and shall be continuously tapered with longitudinal welding. There shall not

be any circumferential welding. Monopoles shall be of two or more section

with telescopic joint as per the required height.

To join two or more sections either of two joints are being used:

1.Slip Joint

2.Flange joint

Slip joint:

Slip joints shall be designed to resist the maximum forces and moments at

0% fthe connection. As a minimum, slip joints shall be designed to resist 50% of

CONSTRUCTION OF MONOPOLE

moment capacity of the lower strength tube. Taper above and below the joint

shall be the same.FLANGE JOINT:

Flange joints shall be designed to resist the maximum forces and moments at

the connection. As a minimum, slip joints shall be designed to resist 50% of

moment capacity of the lowest strength tube. Flexure stress in flange

connection shall not exceed the specified minimum yield stressconnection shall not exceed the specified minimum yield stress

Monopoles are constructed from High Tensile steel conforming to IS 2062 orp g g

BSEN 10025 and cut in Trapezoidal shape and folded by pressing to required

angle and Welded Longitudinally to form Polygonal section.

PROCESS OF MANUFACTURING: HIGH MASTS

H.R.COIL

SEAM WELDING

BASE PLATE WELDING

S.A.W

CUT TO LENGTH

BENDING TO

CUT TO LENGTH

BENDING TOPOLYGON

(PRESS BREAK) HOT DIP GALVANIZING

CUT TO LENGTH CUT TO LENGTH

H.R COILS are loaded on the Cut To

Length machine.

C.T.L Machine Cuts the Coil in required

width & and applies constant pressurewidth & and applies constant pressure

to maintain the Uniformity in thickness.

PRESS BREAK MACHINEPRESS BREAK MACHINEFOLDING:

After cutting the coil in the required

trapezium. It is then folded to the

numbers of folds. By applying the

load under the press break machine.

WELDINGThere shall not be any circumferential

welding. The welding of pole shaft shall

be done by Submerged Arc Welding

(SAW) process.

All Monopole shafts shall be provided

with the rigid flange plate of suitable

thickness with provision for fixingthickness with provision for fixing

foundation bolts. This base plate shall be

fillet welded to the Monopole shaft at two

locations i.e. from inside and outside.

The welding shall be done as per

lifi d d b Thi dqualified approved process by Third

Party Inspection agency.

Metal protection:

For metal protection of the Monopole, the entire fabricated Monopole is hot dip

galvanized internally and externally.

Galvanization is the process of applying a protective zinc coating to metal, in

order to prevent rusting and galvanic corrosion. Although galvanization can be

d ith l t h i l d l t d iti th tdone with electrochemical and electro deposition processes, the most common

method in current use is hot-dip galvanization, in which steel parts are

submerged in a bath of molten zinc.submerged in a bath of molten zinc.

Galvanization shall be confirming to BSEN 1461:1999 or equivalent.

POLE WITH 2-PART INSULATORS

Areas where electrical clearance is an issue and

t bl t d ione can not able to design pole with arms with proper dimensions it can be replaced by insulated ep aced by su a edcross arms (2-part insulator).Use of insulated cross arm also reduce the manufacturing time.

FOUNDATIONFOUNDATIONThe design of foundation consists of two parts – Stability analysis and structural design of foundation. The following subsection describes in detail about the two aspects.

Stability analysis aims at eliminating the possibility of failure of foundation by tilting, overturning, uprooting and siding due to load i t it i d il b f d ti Th t i t t t fintensity imposed on soil by foundation. The most important aspect of the foundation design is the necessary check for the stability of foundation under various load conditions.

1 Check For Bearing Capacity1. Check For Bearing Capacity.2. Check for Overturning Resistance.3. Check For Sliding.4 Check for Uplift4. Check for Uplift.

Structural design of concrete foundation comprises the design of base slab/Pedestal/block. The structural design of different elements ofslab/Pedestal/block. The structural design of different elements of concrete foundation.

TYPE OF FOUNDATIONTYPE OF FOUNDATIONDifferent Types of Foundation Are;

Shallow foundation / Raft FoundationPile foundationBuried foundation / Block Foundation

selection of type of foundation depends on various parameters such as,1. Type of soil / soil stratum.2. Intensity of load.3. Space availability.4. Economy.

Monopole Structure being Cantilever structure ,Moments at the base are critical.Due to heavy Overturning Moment shallow foundations are not cost effective, asthe Large base area is required for stability.

O fFor Intense Overturning Moments, Pile foundation can be economical.

SHALLOW FOUNDATIONSHALLOW FOUNDATION

Shallow foundations can be recommended for the Lower intensity Loading.

Shallow foundation Design is Governed by ,S.B.C of Soil :- Size of foundation & its dimensions are governed by S.B.Cof Soil. Gross Pressure shall be maintained Lower than S.B.C of Soil.Stability Against Overturning :- To prevent the overturning / Tilting offoundation at toe, foundation size is decided so that the Restoring Monet dueto dead Load is greater than overturning Moment For Economic designto dead Load is greater than overturning Moment. For Economic designEarth cone shall be considered for Calculating the Dead Load ,Also Uplift of20% can be permitted.Stability Against Sliding :-The friction between bottom of the footing and soilStability Against Sliding : The friction between bottom of the footing and soilresist the sliding of footing and shall be considered in the stability of foundationagainst sliding.

PILE FOUNDATIONPILE FOUNDATIONFor the Structures where the large moments are to be transferred to theSubstructure, Pile Foundation shall be adopted.

Type of Pile are classified as,1. End Bearing pile :- In this case the Pile is socketed in Hard Stratum & Load

i T f d b B i I i Ad d i H d R kis Transferred by Bearing. It is Adopted in Hard Rock.2. Friction Pile :- In this Load Transfer is by the negative Skin Friction, that

develops between the wall of Pile & Soil in contact with it. It is Adopted inCohesive soilCohesive soil.

Pile foundation Design is Governed by ,Capacity of Pile:- Capacity of Pile depends on its Length & Soil propertiesCapacity of Pile:- Capacity of Pile depends on its Length & Soil properties.No of Pile:- Based on the Capacity of Pile, No of pile & its arrangementrequired to carry the tension or compression is decided.

BURIED FOUNDATIONBURIED FOUNDATION

In buried type foundation, resistance to overturning is evaluated assuming thati th diti d l d ti l j ti bpassive earth pressure conditions are developed on vertical projections above

the toe of foundations.Buried Type foundations are the Most Economical Foundations. It can beadopted for the structures where the Moment at the Base are less For Antennaadopted for the structures where the Moment at the Base are less.For AntennaMonopoles Buried Type foundation can be used, As the design is governed bythe Deflection & moments at the base of monopole are less

Advantage of Buried foundation:• For buried foundation base flange is not required.• For buried foundation Bolts are not required.• With this erection is faster.

APPLICATIONS OF MONOPOLEAPPLICATIONS OF MONOPOLE

Transmission & Distribution: Monopoles are latest Alternative to Overhead & p

Transmission Lines lattice type self supporting towers. Widely being used in

Gulf & European Countries.

CCTV Mast: Monopole structures are also used for mounting of CCTV

Cameras.

Telecommunication: Monopole structures are ideal for mounting antennas

for telecommunication.

Signage's: Monopole structures Can be used for Unipole SignageSignage s: Monopole structures Can be used for Unipole Signage

structures.

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CRITERIA FOR DEFLECTION:

Monopole structure being slender structure large deflection can be permitted,

as long as it does not affect its utilityas long as it does not affect its utility.

As there is no criteria for deflection, where deflection is considered critical it

may be limited to 5% of the total height.

TRUE SCALE TESTING

TESTING:TESTING:Type testing or destruction testing of Monopole

structures can be carried out in the similar way

as that of Transmission Latticed Tower.

/Transmission line Monopoles /

distribution Poles can be tested for true

scale loading.scale loading.

The prototype shall be made of material

that is representative of the material that

will be used in production.

Completely Automatic Tower Testing Station (Upto 85m Structure) - Gammon Plant at Deoli

TRUE SCALE TESTING

Mill test report shall be available for h j t i th t t

TEST NO.

TESTCASES

DESCRIPTION

each major component in the test structure.Load lines shall be attached to the load point on the prototype in a

1. Case 1(100%)

Reliability condition,32o C & full wind.

2. Case 2 Reliability condition, load point on the prototype in a manner that simulates the in-service application as close as possible.

2. Case 2(100%)

Reliability condition,32o C & full wind, Single circuit strung.

3. Case 3(100%)

Security condition,32o C & Nil i d T d t b k Wind-on-structure loads shall be

applied as concentrated loads at selected points on the structure.Load application shall consider the

(100%) wind, Top conductor broken.

4. Case 4(100%)

Safety condition,32o C & Nil wind, Bottom conductor Stringing Load application shall consider the

deflected position of structure. Sequence of load cases tested given in tab.1.

Stringing.

5. Case 5(100%)

Security condition,32o C & 75% Full wind, Ground wire broken. given in tab.1.

Testing Facility is available at ‘Deoli

Plant‘ at Maharashtra.6. Case 6

(100%)Security condition,32o C & 75% Full wind, Top conductor broken.

PROJECTS UNDERTAKENPROJECTS UNDERTAKEN

CLIENT- Adani Town ship & Real estate Ltd.

PROJECT- 66Kv D/C 3.1KmsTransmission Line

SOFTWARE USEDSOFTWARE USED- Pls_Pole (Power Line System)

CONDUCTOR – ACSR PANTHER

GROUND WIRE- GSW(Galvanized Steel Wire)

SPAN- 230 Mts.

TYPE OF POLES-

PA TYPE- 0-2 Deg Suspension monopole


PB TYPE- 0-30Deg Tension Monopole

PC TYPE- 60-90Deg Tension Monopole

Pole Design/Loads on Pole Structure is as per Loading condition given in o e es g / oads o o e St uctu e s as pe oad g co d t o g eIS:802(part1/sec1):1995

Pole analysis is carried as per ASCE/SEI 48-05.


CLIENT- Jaguar Overseas

PROJECT- Electrification Project of 58 Rural Localities city of Benin ,Distribution poles

Octagonal distribution Poles Description is given below:13 Mtr- 430 daN13 99013 Mtr- 990daN13 Mtr-1220 daN11 Mtr-1250 daN11.9 Mtr- 430 daN11.9 Mtr- 990 daN11.9 Mtr- 1220 daN14 Mtr- 1250 daN


CLIENT- OIA( Overseas Infrastructure Alliance )

PROJECT- Rural Electrification project ,Mozambique

Octagonal Distribution Pole description MV 11Mtr.LV 8 Mtr.

ADVANTAGE OF MONOPOLE STRUCTUREADVANTAGE OF MONOPOLE STRUCTURE

Space consumed by a monopole compared to a lattice structure of same capacity is much

less. Hence monopole structures become suitable for heavily populated and congested

areas like metros and other cities.

The Project using Monopole are less subjected to ROW / Corridor problemsThe Project using Monopole are less subjected to ROW / Corridor problems.

As the Number of Pieces of monopoles are much lesser than the Lattice tower Structure

the chances of failure are less.

Poles are subjected to lesser wind load as compared to Tower structure, Due to smaller

aerodynamic coefficient.

Poles being Continuum Type offer more resistance to terrorist activities as compared withPoles being Continuum Type offer more resistance to terrorist activities as compared with

the lattice Structure.

Since the space consumed is less, the spotting shall very well be optimized.

Aesthetically Monopoles has pleasant appearance.

E ti f l i 3 t 4 ti f t th l l tti t t tErection of monopoles is 3 to 4 times faster than normal lattice type structures

As the Body width of Monopole Structure is smaller than, Lattice Structures it helps in

Reduction physical dimensions as per the Clearances required. Pole Structures Should be

Considered Flexible & Relatively large Deflections can be permitted. The deflection of

Structure & Swing of Insulator can Significantly decrease wire Tension.Structure & Swing of Insulator can Significantly decrease wire Tension.

Monopole structure being slender & Slip Jointed, has good damping properties. At Steady

i d it h hi h A lit d f ib ti ith d d i f b t 0 2 0 3wind pressure it has higher Amplitude of vibration with good damping of about 0.2 – 0.3.

LIMITATIONS OF POLE STRUCTURESLIMITATIONS OF POLE STRUCTURES

As compared to the Lattice structure, monopoles are expensive.

Monopole Structure being Cantilever structure ,Moments at the base are critical

Due to heavy Overturning Moment shallow foundations are not cost effective.

As Monopole structure is constructed from the sheet wastage of Material isAs Monopole structure is constructed from the sheet, wastage of Material isHigher.

For installation of Monopole Structure Heavy cranes are required.

CONCLUSION

Transmission Line on Monopole can be cost effective in the urban areas, where the land price is high.T i i Li M l h l t & It i t t ll t blTransmission Line Monopole has pleasant appearance & It is structurally more stable.Limiting the defection to one or one half percent (1 or ½%) of the structure height underconstruction loading can eliminate the need for back guying structures duringconstruction. For appearance, limiting deflections to five or ten percent (5 or 10%) of thestructure height under maximum loading can keep a pole in a position. Anothertechnique that is used to keep steel pole structure appearance aesthetically pleasing isto camber or rake the structures before erection. Cambering or raking makes thestructure initially deformed so that when load is applied to the structure, it tends tobecome straight or appears less deformed.Sometimes, client restricts the base diameter due to space or other constraints thatindirectly limit the amount of taper. In such a case, the design output is only the wallthickness of pole segments that is adjusted to satisfy all the design criteria.g j y gIn steel pole structures, the maximum allowable stress on the pole is related to the widthto thickness ratio for structures with polygonal cross-sections and by diameter tothickness ratios for structures with circular cross-sections.

Poles, being flexible structures, are subjected to considerably large deflections e.g.1 to 1 5m The major contribution in these deflections is from lateral loads which1 to 1.5m. The major contribution in these deflections is from lateral loads, whichare further increased by vertical loads due to P-Δ effects. For the tangent poles,this large deflection will be infrequent and occasional in its entire life span (i.e.when it is subjected to worst possible high wind/lateral loading). Hence, theselarge deflections need not to be controlled For angle poles however lateral loadslarge deflections need not to be controlled. For angle poles, however, lateral loadsare not casual which cause permanent large lateral deflections.Most of the poles consist of 3 to 4 segments. A single pole segment usually has aneconomical and optimal length of 12m. The minimum thickness of material usedf l i ll 4for poles is usually 4mm.Weight of Monopole structure is higher as compared to Lattice Structure.

PROCESSING AN EXPORT ORDER

COST COMPARISONCOST COMPARISONCOMPARISON OF MONOPOLE WITH LATTICE STRUCTURE

220 Kv DOUBLE CIRCUIT MONOPOLE

SPAN - 300MS 300

CONDUCTOR - ZEBRA

WT OF R C C M25TYPE OF STRUCTURE BASE WIDTH WT OF STRUCTURE

R.C.C -M25 Gr STEEL APPROX COST

LATTICE TYPE 8M X 8M 5 M.T 5 CU.M 600 KG 3500000

MONOPOLE 2M X 2M 8.1 M.T 35 CU.M 3200 KG 1000000

PROJECTS EXECUTEDPROJECTS EXECUTED

Pallekele Cricket Stadium, Kandy

Gandhidham, Kutch

Kudlagi, Bellary MCA Cricket Stadium, Pune

Punjab University Campus

Shivaji Terminal Delhi Metro

Telecom Monopole, Th

IFFCO Township, Campus, Chandigarh

Delhi Metro Station, New Delhi

Thane Paradip

Transrail Lighting Stadium Masts at World Cup Cricket Venue -P ll k l (K d ) S i L kPallekele(Kandy), Sri Lanka

PROCESSING AN EXPORT ORDERPROCESSING AN EXPORT ORDER

THANK YOUTHANK YOU

Transmission Monopole

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