PROJECT REPORTPROJECT REPORTonon

Course No. 10109Course No. 10109

By-By-

T.VIJAYAKUMAR AXEN/FBW/AJJ, S. RLYT.VIJAYAKUMAR AXEN/FBW/AJJ, S. RLY

S.ARUMUGAM ARULAPPAN AXEN/CN/TBM, S.ARUMUGAM ARULAPPAN AXEN/CN/TBM, S.RLYS.RLY

H.S.SAXENA, AXEN(CON)/CCG, W. RLYH.S.SAXENA, AXEN(CON)/CCG, W. RLY

AcknowledgementAcknowledgement

We are grateful to –We are grateful to –

Sri V.B.SOOD, Professor BridgesSri V.B.SOOD, Professor BridgesWho has guided us right through the study of this projectWho has guided us right through the study of this project..

We are also thankful to-We are also thankful to-

Sri N.K.KHARE, Course Director.Sri N.K.KHARE, Course Director.For having helped us in training programme.For having helped us in training programme.

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INTRODUCTIONINTRODUCTION Open web girders are used for track bridges over valleys Open web girders are used for track bridges over valleys

and large rivers.and large rivers. Standard length of open web girders in railways are Standard length of open web girders in railways are 30.5, 30.5,

45.7, 61.045.7, 61.0 and and 76.276.2 metres. metres. Engineering workshops, Arakkonam is fabricating welded Engineering workshops, Arakkonam is fabricating welded

type girder since 1981. Present production capacity is type girder since 1981. Present production capacity is 80 80 MT MT per month. per month.

With the past experience in welded girder fabrication, this With the past experience in welded girder fabrication, this workshop taken up the work of fabrication open web girder workshop taken up the work of fabrication open web girder 30.5m span for SC Railways in 30.5m span for SC Railways in Purna - AkolaPurna - Akola section. section.

Subsequently EWS/AJJ has manufactured 4 spans of open Subsequently EWS/AJJ has manufactured 4 spans of open web girder 45.7m span for Nethravathi Bridge. web girder 45.7m span for Nethravathi Bridge.

Presently, fabrication of 61.0m riveted type girder of 10 Presently, fabrication of 61.0m riveted type girder of 10 spans for North Eastern Railway is under progress.spans for North Eastern Railway is under progress.

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SALIENT FEATURES OF SALIENT FEATURES OF OPEN WEB GIRDEROPEN WEB GIRDER

RDSO Drg No. BA – 11461 to BA – 11479 RDSO Drg No. BA – 11461 to BA – 11479 (M.B.G. Standard)(M.B.G. Standard)

Weight of girder – 65 MTWeight of girder – 65 MT Overall length of girder – 32.460mOverall length of girder – 32.460m Effective length of girder – 31.926m (Center Effective length of girder – 31.926m (Center

to center of Bearings)to center of Bearings) Height of girder – 7.637mHeight of girder – 7.637m Width of girder – 5.760m Width of girder – 5.760m Type of loading – MBG LoadingType of loading – MBG Loading

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Flow Process Chart for Fabricating Open Web GirderFlow Process Chart for Fabricating Open Web Girder

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INSPECTION OF WELDED INSPECTION OF WELDED TYPE GIRDERSTYPE GIRDERS

INSPECTION BEFORE WELDINGINSPECTION BEFORE WELDING

INSPECTION DURING WELDINGINSPECTION DURING WELDING

INSPECTION AFTER WELDINGINSPECTION AFTER WELDING

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INSPECTION BEFORE INSPECTION BEFORE WELDINGWELDING

Inspection of raw steel and its conformation to IS : 2062 Gr. Inspection of raw steel and its conformation to IS : 2062 Gr. ‘B’ killed and normalised variety for plates over 12 mm thick. ‘B’ killed and normalised variety for plates over 12 mm thick.

For plates of 10 mm and 12 mm thick, the condition of For plates of 10 mm and 12 mm thick, the condition of normalisation is not necessarynormalisation is not necessary. .

In the absence of SAIL or Mill certificate, samples of plates In the absence of SAIL or Mill certificate, samples of plates with code no. are being tested at ACMT/LAB/EWS/AJJ.with code no. are being tested at ACMT/LAB/EWS/AJJ.

Preparation of welding procedures specification sheets for Preparation of welding procedures specification sheets for various welds involved in the fabrication of a particular span.various welds involved in the fabrication of a particular span.

Welding procedure qualification records and approval of Welding procedure qualification records and approval of welders are to be taken up after the approval of WPSS is welders are to be taken up after the approval of WPSS is received. (Ref. IS - 7307 part I and IS – 7310 part I). received. (Ref. IS - 7307 part I and IS – 7310 part I).

Whether welding consumables are of the brands as per the Whether welding consumables are of the brands as per the latest instructions received from RDSO, as supplemented to latest instructions received from RDSO, as supplemented to IRS-M.28 and IRS-M.39.IRS-M.28 and IRS-M.39.

Transferring of cast number to cut pieces from parent metal.Transferring of cast number to cut pieces from parent metal.

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INSPECTION DURING WELDINGINSPECTION DURING WELDING

Checking whether approved welding consumables are Checking whether approved welding consumables are used by the welders.used by the welders.

Checking whether the approved welders do the weld.Checking whether the approved welders do the weld. Checking the approved parameters for welding is Checking the approved parameters for welding is

being employed and are being recorded in the being employed and are being recorded in the register.register.

Checking for any distortions and suggesting methods Checking for any distortions and suggesting methods to minimize them.to minimize them.

Marking defects etc observed during the inspection for Marking defects etc observed during the inspection for rectification.rectification.

Attempts to make I-section or any other member is Attempts to make I-section or any other member is permitted only after passing Radiographic Test on the permitted only after passing Radiographic Test on the Butt welded joint.Butt welded joint.

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INSPECTION AFTER INSPECTION AFTER WELDINGWELDING

The fillet welds are checked by visual The fillet welds are checked by visual and Dye-penetrant test. and Dye-penetrant test.

Defects noticed are to be rectified and Defects noticed are to be rectified and details are recorded.details are recorded.

Etching tests.Etching tests. Radiographic film test.Radiographic film test.

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VISUAL INSPECTIONVISUAL INSPECTION The finished welds shall be visually inspected and shall The finished welds shall be visually inspected and shall

conform to the size and contour specified in the conform to the size and contour specified in the drawing. drawing.

The following types of defects can be detected during The following types of defects can be detected during visual inspection.visual inspection.– Weld defects at the surface such as blow holes, Weld defects at the surface such as blow holes,

pipes, exposed porosity, exposed inclusions, etc.pipes, exposed porosity, exposed inclusions, etc.– Surface cracks in the weld metal or in the parent Surface cracks in the weld metal or in the parent

metal adjacent to it.metal adjacent to it.– Damage to the parent metal such as undercut, Damage to the parent metal such as undercut,

burning, overheating, etc.burning, overheating, etc.– Profile defects such as excessive convexity, Profile defects such as excessive convexity,

concavity or unequal leg lengths etc.concavity or unequal leg lengths etc.– Incorrect finish, uneven welds, spatter, etc.Incorrect finish, uneven welds, spatter, etc.

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DYE PENETRANT TESTDYE PENETRANT TEST In the dye or liquid penetrant testing, a suitable liquid In the dye or liquid penetrant testing, a suitable liquid

penetrant is applied to the surface of the portion under penetrant is applied to the surface of the portion under examination and remains there for a sufficient time to examination and remains there for a sufficient time to allow the liquid in to any defect open at the surface. allow the liquid in to any defect open at the surface.

After the penetration time, the excess penetrant which After the penetration time, the excess penetrant which remains on the surface is removed. remains on the surface is removed.

Then, a light color absorbent called developer is applied Then, a light color absorbent called developer is applied on the surface. on the surface.

This developer acting as a blotter draws out a portion of This developer acting as a blotter draws out a portion of penetrant which had earlier seeped in to the surface penetrant which had earlier seeped in to the surface opening.opening.

As the penetrant is drawn out, it diffuses in to the coating As the penetrant is drawn out, it diffuses in to the coating of the developer forming the indication of the surface of the developer forming the indication of the surface discontinuities as a flaws.discontinuities as a flaws.

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Defects noticed in Defects noticed in D.P. TestD.P. Test

Blow hole ( Enlarged view )

After rectification of defects

ETCHING TESTSETCHING TESTS

Etching tests on run-off coupons and Etching tests on run-off coupons and at the edges of girders for checking at the edges of girders for checking the root fusion and throat length. the root fusion and throat length.

Etching tests are conducted on Etching tests are conducted on smooth, clean surface by –smooth, clean surface by –

– applying 2 % nitric acid.applying 2 % nitric acid.– cleaning it with water.cleaning it with water.– cleaning it with alcohol cleaning it with alcohol

Then check the leg length, throat and Then check the leg length, throat and penetration and recording the details penetration and recording the details in Etching Test Register.in Etching Test Register.

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RADIOGRAPHIC FILM TESTRADIOGRAPHIC FILM TEST

Butt joints, if any, have to be done by submerged arc Butt joints, if any, have to be done by submerged arc welding and radiography (Gamma Ray) testing has to welding and radiography (Gamma Ray) testing has to be done to ensure the quality of weld. be done to ensure the quality of weld.

In radiography, the ability of short wave length In radiography, the ability of short wave length radiations such as X-ray and Gamma rays to penetrate radiations such as X-ray and Gamma rays to penetrate the object opaque to ordinary light is utilized to the object opaque to ordinary light is utilized to produce a shadow of any internal defect or image. produce a shadow of any internal defect or image.

To check the Internal defects of weld in Butt Weld To check the Internal defects of weld in Butt Weld Joints on Flange and Web plate Joints.Joints on Flange and Web plate Joints.

For radiographic examination, Iridium 192 isotope is For radiographic examination, Iridium 192 isotope is used. Radiographic tests are conducted as per IS : used. Radiographic tests are conducted as per IS : 1182 / 1983.1182 / 1983.

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NUMBERING OF PANEL NUMBERING OF PANEL POINTSPOINTS

30.5 m Span OWG30.5 m Span OWG

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CAMBER IN STEEL GIRDERCAMBER IN STEEL GIRDER

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CAMBER IN STEEL GIRDER – CAMBER IN STEEL GIRDER – Contd..Contd..

Steel triangulated (open web) girders are Steel triangulated (open web) girders are provided with camber to compensate the provided with camber to compensate the deflection under load.deflection under load.

Out of the total design camber, the part Out of the total design camber, the part corresponding to dead load is called dead load corresponding to dead load is called dead load camber. camber.

The balance is called live load camber which The balance is called live load camber which should be available as visible and measurable should be available as visible and measurable camber in the girder when not carrying the camber in the girder when not carrying the live load live load

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MAIN COMPONENTS OF MAIN COMPONENTS OF OPEN WEB GIRDEROPEN WEB GIRDER

PRIMARY MEMBERSPRIMARY MEMBERS

SECONDARY MEMBERSSECONDARY MEMBERS

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PRIMARY MEMBERSPRIMARY MEMBERS

Bottom chord Bottom chord Top chord Top chord End Rakers End Rakers Diagonals Diagonals Vertical members Vertical members Floor system Floor system

– Cross girders Cross girders – Rail bearers or stringers Rail bearers or stringers

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SECONDARY MEMBERSSECONDARY MEMBERS

Bottom lateral bracingsBottom lateral bracings Top lateral bracingsTop lateral bracings Sway bracings and knee swaySway bracings and knee sway Portal bracings and knee portalPortal bracings and knee portal Corner bracketsCorner brackets End stools and end bracketEnd stools and end bracket Main gussetsMain gussets Bearings Bearings

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BOTTOM CHORDBOTTOM CHORD

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TOP CHORD TOP CHORD

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END RAKERSEND RAKERS

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DIAGONALSDIAGONALS

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VERTICAL MEMBERSVERTICAL MEMBERS

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FLOOR SYSTEM – FLOOR SYSTEM – CROSS GIRDERSCROSS GIRDERS

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FLOOR SYSTEM – FLOOR SYSTEM – RAIL BEARERS OR STRINGERSRAIL BEARERS OR STRINGERS

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TRIAL ASSEMBLY AT THE TRIAL ASSEMBLY AT THE WORKSHOPSWORKSHOPS

Selection of assembly siteSelection of assembly site

Erection facilitiesErection facilities

AssemblyAssembly

Camber measurementCamber measurement

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SELECTION OF ASSEMBLY SITESELECTION OF ASSEMBLY SITE

The assembly of Girder has to be The assembly of Girder has to be done on a firm and leveled platform. done on a firm and leveled platform.

Hence, the concrete platform Hence, the concrete platform available nearby the Structural Shop available nearby the Structural Shop was selected. was selected.

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ERECTION FACILITIESERECTION FACILITIES

Road mobile crane was utilized for Road mobile crane was utilized for erection. erection.

Gantries and Hoist were arranged since Gantries and Hoist were arranged since the height of the crane was only 9m and the height of the crane was only 9m and the requirement was about 10m for the requirement was about 10m for handling the top chord and diagonal.handling the top chord and diagonal.

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ASSEMBLYASSEMBLY

The bed for assembly was made with ISMB 400 mm and packing plates about 200mm to facilitate assembly.

The bed was checked and leveled with water level.

Contd..• Bottom chords 2 nos. were

laid from one end with bottom gussets and the cross girders assembled in between bottom chords, also stringers in between cross girders.

Contd..Contd..

Black bolts 50 % Black bolts 50 % and drifts 50 % are and drifts 50 % are used for connecting used for connecting the joints. (In fields the joints. (In fields 40 % holes filled 40 % holes filled with drifts and with drifts and remaining with remaining with black bolts as per black bolts as per manuals.)manuals.)

Contd..Contd.. Similarly the successive Similarly the successive

bottom chords were laid with bottom chords were laid with cross girders and stringers.cross girders and stringers.

Bottom laterals were Bottom laterals were assembled in position.assembled in position.

The cross measurement and The cross measurement and diagonal measurements diagonal measurements checked and tightened all checked and tightened all the black bolts.the black bolts.

Insert the camber jacks over Insert the camber jacks over platform below every bottom platform below every bottom panel joints in such away panel joints in such away that all the joints are in run that all the joints are in run out condition except central out condition except central jack.jack.

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Contd..Contd.. Levels were taken at top of Levels were taken at top of

bottom chord at every nodal jointbottom chord at every nodal joint

Erect all the vertical members at Erect all the vertical members at nodal point and diagonals were nodal point and diagonals were fixed subsequently with fixed subsequently with temporary gussets. (Gussets temporary gussets. (Gussets holes are drilled for the camber holes are drilled for the camber profile)profile)

Check to ensure that bottom Check to ensure that bottom chords is in one level.chords is in one level.

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Contd..Contd.. Provide camber to all panel joints of bottom chords as per Provide camber to all panel joints of bottom chords as per

camber diagram by lowering the jacks at the ends, keeping camber diagram by lowering the jacks at the ends, keeping central jacks with out disturbing.central jacks with out disturbing.

Check the camber readings and adjust for correctness.Check the camber readings and adjust for correctness.

contdcontd Top chord members are to be elastically strained, so that Top chord members are to be elastically strained, so that

erected from centre to outwards.erected from centre to outwards. Temporary gussets were replaced with permanent gussets Temporary gussets were replaced with permanent gussets

before drifting.before drifting. Drifts are driven with hammer, check for trueness of holes Drifts are driven with hammer, check for trueness of holes

in the adjacent group holes.in the adjacent group holes. Care should be taken so that holes are not damaged.Care should be taken so that holes are not damaged.

( elongated or teared).( elongated or teared).

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Contd..Contd.. 5 Ton Pulley block was used for 5 Ton Pulley block was used for

assembling the members to keep assembling the members to keep the joint in position. the joint in position.

End Rakers were erected in the End Rakers were erected in the last, the upper end was first last, the upper end was first connected and drifted, then connected and drifted, then connection was made at lower end. connection was made at lower end.

Sway bracings, top laterals Sway bracings, top laterals bracings and portal bracing were bracings and portal bracing were erected subsequently.erected subsequently.

All joints were tightened and All joints were tightened and drifted.drifted.

Contd..Contd.. Lowered the jacks duly keeping Lowered the jacks duly keeping

the end supports in position.the end supports in position. Dead load camber was checked by Dead load camber was checked by

leveling instrument, also with leveling instrument, also with water level. The measurements water level. The measurements recorded as L1-11 mm recorded as L1-11 mm (13.1 mm)(13.1 mm) , , L2- 22 mm L2- 22 mm (21.0 mm)(21.0 mm) , L3- 26 mm , L3- 26 mm (26.3 mm)(26.3 mm) ,L4- 22 mm ,L4- 22 mm (21.0 mm)(21.0 mm) and L5- 10 mm and L5- 10 mm (13.1 mm).(13.1 mm).

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COST OF THE GIRDERCOST OF THE GIRDER (Per MT)(Per MT)

Revenue RateRevenue Rate

DescriptiDescriptionon

Cost Cost (in (in Rs.)Rs.)

StoresStores 41459.41459.0404

LabourLabour 26791.26791.9898

Labour Labour OncostOncost

31346.31346.6262

Stores Stores OncostOncost

1607.51607.522

TotalTotal 101201012055

Home Rly. RateHome Rly. Rate

DescriptionDescription Cost Cost (in Rs.)(in Rs.)

Revenue Revenue RateRate

101205.0101205.000

Proforma Proforma Oncost @ Oncost @ 41%41%

23836.8323836.83

FreightFreight 3014.663014.66

Total Total 128057128057

Foreign Rly. RateForeign Rly. Rate

DescriptioDescriptionn

Cost Cost (in Rs.)(in Rs.)

Revenue Revenue RateRate

101205.101205.0000

Proforma Proforma Oncost @ Oncost @ 91%91%

52906.152906.133

FreightFreight 3014.663014.66

SupervisionSupervision 4608.124608.12

ProfitProfit 10882.710882.799

Total Total 172617172617

PROBLEM ENCOUNTERED & PROBLEM ENCOUNTERED & REMEDIAL MEASURES.REMEDIAL MEASURES.

The Bottom chords after fastening with bolts and The Bottom chords after fastening with bolts and drifting, the jacks were lowered for the camber drifting, the jacks were lowered for the camber but due to the shorter length of bottom chord but due to the shorter length of bottom chord member, the camber not formed.member, the camber not formed.

Solution:Solution: The bottom chord joints were loosened and The bottom chord joints were loosened and

replaced with under size bolts and also removed replaced with under size bolts and also removed drifts , then achieved the required camber after drifts , then achieved the required camber after erecting the top chord and end rakers. erecting the top chord and end rakers.

Care was taken to drive the drifts and close Care was taken to drive the drifts and close supervision was made to avoid elongation and supervision was made to avoid elongation and tearing of drilled holes in gussets and members.tearing of drilled holes in gussets and members.

PROBLEM ENCOUNTERED & PROBLEM ENCOUNTERED & REMEDIAL MEASURES.REMEDIAL MEASURES.

Leveling instruments were tried to measure Leveling instruments were tried to measure the camber. It was a failure due to the poor the camber. It was a failure due to the poor accuracy in reading on a length of 30M.accuracy in reading on a length of 30M.

Measuring of camber with Piano wire 0.5mm Measuring of camber with Piano wire 0.5mm DIA, 10 kg weight at both end as per bridge DIA, 10 kg weight at both end as per bridge code was a failure due to sag in 30M length.code was a failure due to sag in 30M length.

Solution:Solution: Water level with a diameter of 6 mm and Water level with a diameter of 6 mm and

length of 40M was used to check the level of length of 40M was used to check the level of the girder.the girder.

PROBLEM ENCOUNTERED & PROBLEM ENCOUNTERED & REMEDIAL MEASURES.REMEDIAL MEASURES.

Slight deformation of the chord members Slight deformation of the chord members fabricated by welding has been observed and fabricated by welding has been observed and some gap was formed between top chord end some gap was formed between top chord end and junction U1. and junction U1.

Solution:Solution: Jacks were used to close the gap by lifting the Jacks were used to close the gap by lifting the

floor system. Further, 5 Ton pulley block was floor system. Further, 5 Ton pulley block was used to erect the member in position.used to erect the member in position.