The document discusses the construction of a steel superstructure for a rail-cum-road bridge across the River Ganga in Bihar, India. Key details include a bridge length of 3.690 km using welded steel truss construction. Gammon Infrastructure Projects Ltd has been contracted to fabricate and erect 12 spans of 125m each. The work involves fabricating over 24,000 tons of structural steel at site workshops and erecting the spans by cantilever erection using customized cranes. Challenges include avoiding distortion during fabrication and controlling cantilever erection stresses.

1. 17.01.2014

2.  Project Name Construction of Steel Superstructure
for Rail-cum-Road Bridge Across River
Ganga at Munger in Bihar
 Job code No. 8802
 Location Between Munger & Khagaria in Bihar
 Similar Bridge Across river Brahmaputra in Assam
 Importance To provide a long awaited connectivity
 Description Two lane Road & single Railway track
 Bridge Length 3.690 Km
 Superstructure Welded Steel Truss (riveted joints)

3. Munger
Bridge

4.  Employer East Central Railway, Patna
 Client BBJ Construction Co Ltd, Kolkata
 Contract Value Rs 375.19 Crores
 Completion Period 30 months
 Span Arrangement 1 x 32.6 + 29 x 125 + 1 x 32.6
 Type of Superstructure THROUGH TYPE WELDED STEEL TRUSS
 Weight of 125m Span 1885 MT/Span
 Width/Depth of 125m Span 13.35m/18.5m
 Gammon Scope 12 x 125
 Quantity of Structural Steel 24770
 Site Joints Riveted
 Ancillary Works RCC Deck, Bearing Pedestals, Exp Joints

5. Khagaria end
Munger
End
P 29
P28

7. Top Chord Members
Bottom Chord Members
Diagonals
Verticals
End Raker
Road Deck
Rail Track

8. Matching point of North and Sounth End

10. Item Features
Type of span Welded girder with riveted connection
at joints
Height / Width of span 19.68m / 13.0m outside dimension
No of members in one span 417 members
No load & Dead Load camber 181.35 mm & 112.5 mm at center
Weight of one span 1885 MT
Max weight of single lift 25 MT (1st Bottom Chord after assembly)
Type of welding in members Submerged Arc Welding / MIG Welding
Type of steel being used E 250B, E 350Cu, E 450Cu (Normalized,
Fully Killed)

11. Item Code no. Item covered
Steel supply IS :2062: 2006 Steel plates / Rolled section
Fabrication IRS:B1 - 2001 Fabrication
Welding IRC: WBC Metal arc welding in steel
IRS: M-39/M-46/M-28 SAW welding /MIG welding/MMAW
IS:9595 Metal arc welding in carbon steel
IS:7307 (Pt-1) Approval test for welding procedures
IS: 7310 (Pt-1) Approval test for welders
Ultrasonic Testing ASTM (SA 578/ 578M)/ IS:4225 UT of plates
IS:4260 UT of butt welds
Riveting IS:1148 /IS:1149 Steel rivet bars / HT Steel rivet bars
IS: 1929 Hot forged steel rivets
Painting IS:9954 Surface preparation (Sand Blasting)
IS: 5666 Etch primer
IS:104 / IS:2074 Zinc chrome Primer (Yellow) /(Red
Oxide)
IS:2339/IS:2590 Aluminum paints /Aluminum for
metalizing
Erection IRS- B1 :2001 Erection of steel members

12. A SUPPLY, FABRICATION
 Supply Steel of Grade Fe 410W & Fe 490
 Unloading, Stacking
 Fabrication of Members at Site Workshop
 Trial Assembly & Dismantling
 Shop Riveting, where necessary
 Sandblasting & Metalizing/Painting
 Span wise Stacking

14. B ERECTION
 Transportation & Pre-Assembly
 Erection of Truss by Cantilever Method
 Field Riveting
 Alignment & Lowering on Bearings
 Grouting of Bearings
 Final Painting

15. For Entire Bridge Length
 Concreting of Bearing Pedestals
 Concreting of RCC Deck of Bridge
 Installation of Crash Barriers
 Installation of Expansion Joints
 Road Surfacing
 Road Marking

16. A FOR FABRICATION
 Camp Establishment at Khagaria End
 Fabrication Workshop – 3 nos
 Layout Platform
 Establishment at Munger End (BBJ Yard)
 Trial Assembly & Stacking Yard
 Sand Blasting & Metalizing Enclosure
 Feeding track

17. B FOR ERECTION
 Fabrication of Heavy Duty Trestles
 Piling for Anchor Span Supports
 Erection Cranes Design/Manufacture
 Fabrication of Links/Pins
 Fabrication of Strengthening Members
 Staging for Erection/Site Joints
 Scaffolding for Riveting/Painting
 Access Ladders/Platforms/Walkways

18. MOBILISATION
ADVANCE STAGE I
5 % of CV against BGB - 18 % interest
MOBILISATION
ADVANCE STAGE II
5 % of CV against BGB - 18 % interest
PLANT ADVANCE 10 % of CV. Max 75 % of Plant cost.
Hypothecation/BGB for full value of plant.
SECURITY DEPOSIT 10 % of each Bill. Max 5 % of CV.
LIQUIDATED
DAMAGES
Entire amount levied by Railways if contractor
is solely responsible. OR proportionate to their
value of work to total value.
FAILURE IN
EXECUTION OF THE
CONTRACT
Performance guarantee will be encashed & SD
will be forfeited.
SITE FACILITIES TO
BE PROVIDED TO
RAILWAY
Furnished Office, Codes, manuals, 2 vehicles, 6
computers, software, 2 printers, maintenance
personnel, motor boat, walkie talkies etc.

19. MAJOR QUANTITIES
 Mild Steel (Fe 410W) Supply – 8249 MT
 HT Steel (Fe 490) Supply - 16521 MT
 Mild Steel Fabrication/Erection - 7420 MT
 HT Steel Fabrication/Erection - 15162 MT
 Load Test of 125m Span - 3 nos
 RCC M30/M35 - 12900 m3
 Reinforcement - 2100 MT
 Supply of cement - 5779 MT
 Supply of Reinf Steel Fe 500 - 2205 MT
 Design, Supply of Exp Joints
Modular Strip Seal 125m Span - 29 nos
Modular Strip Seal 32.6m Span - 2 nos

20. AS PER CONTRACT AGREEMENT
APPROVED FABRICATION DRAWINGS WILL BE ISSUED BY
BBJ AFTER APPROVAL BY RLYS
MASTER JIGS WILL BE PREPARED AND GOT APPROVED
BY BBJ. GAMMON MAY BE ALLOWED TO MAKE WORKING
JIGS FROM THEM
BBJ WILL PREPARE AND GET ERECTION SCHEME
APPROVED. GAMMON MAY FOLLOW

21. ESCALATION FORMULA BASED ON BASE DATES
/INDICES
1. LABOUR R*(l-lo)/lo*0.3 Consumer price index(RBI) 15.07.2008. 143
2. MATERIAL R*(w-wo)*0.25 Wholesaleprice index-All
commodities(RBI)
15.07.2008. 240
3. FUEL
COMPONENT
R*(F-Fo)*0.15 Wholesaleprice index-
Fuel,Power,Light & Lubricants
RBI)
15.07.2008. 377.2
4. STEEL Ex works price at SAIL+ ED 01.07.2008
a. Reinforcement bars Q*(Bs-Bso) 8 mm dia.
b. M.S.Angles Q*(Bs-Bso) 65x65x6 MM IS 2062.E250A SK
c. Plates Q*(Bs-Bso) PM plates 10 – 20 mm IS 2062 E
250A SK
d. Plates Q*(Bs-Bso) PM plates 10 – 20 mm IS 2062 E
350 cu
Not known.
e. Channels Q*(Bs-Bso) ISMC 200x75 IS 2062 E 250A SK
5. CEMENT R1*(Wc-Wco)/Wco) Wholesaleprice index-Cement (RBI) 15.07.2008 – 222.
R – Gross value Q – cost of steel
supplied during month
R1 – cost of cement consumed
during month

22. MILESTONES
KEY
DATES
REMARKS PENALTY
Submission and approval
of erection scheme for 125
M span
D + 90 days Railways to issue GAD & Stress sheet
15 days from LOI
Railways require 30 days for approval
Rs 2 Lakh
per day. If
contractor
makes up
the progress
within next
two key
dates, then
the penalty
shall be
reimbursed.
Maximum
cumulative
penalty is
@ 3% of CV.
Submission of fabrication
drawings for 125 M span
with complete Design.
D + 150
days
Railways require 30 days for approval.
50% Drawings shall be submitted from
D+60 days and balance 50% drawings
within D + 150 days.
Completion of Trial
assembly of one 125M
span & Pass by Railways.
D + 270
days.
Railways require 21 days for approval.
Trial assembly to be offered with all
test reports, measurements & relevant
doc.
Launching of First span
except placement on
bearings.
D + 300
days.
Launching of Second span
except placement on
bearings.
D + 330
days.
Launching of Fifth span
except placement on
bearings.
D + 390
days.
“D” is issue
Date of
LOA

23.  Award of Contract by BBJ 09.04.2009
 Site Mobilization started on 07.07.2009
 Receipt of Shop Drawings 26.02.2010 onwards
 Receipt of Steel from SAIL 04.03.2010 onwards
 Fabrication Agency Finalized 04.03.2010
 2 no Fabrication Shops Comp 31.03.2010
 Mobilization for Jigs/Fixtures 31.03.2010
 Full Mobilization of Agency 31.05.2010
 Completion of Piers by Rlys 30.06.2010
 Scheduled Completion Date 07.11.2011
 1st EOT granted till Date 31.12.2013
 2nd EOT applied up to 15.06.2015

24. Equipment No's
Hydra (8 T to 14 T Cap) 9 nos.
Handling cranes 2 nos. (45 MT & 50 MT capacity)
EOT cranes 5 nos. (20 MT capacity)
Goliath crane 2 no. (50 MT & 20 MT capacity)
Generators 7 nos. (40 KVA to 500 KVA)
Jacks 10 nos. (100 to 250 MT capacity)
Plate straightening Arrangement 1 nos. (with 2 x 350 MT Jack)
Distortion correction Frame 2 nos.
Compressors 7 nos.
Radial drill machine 15 nos.
Magnetic drill machine 37 nos.
Pug machine 15 nos.
SAW machine for outside welding 13 nos.
SAW machine for inside welding 2 nos.
MIG welding sets 12nos.
MMAW sets 23 nos.
Flux baking furnace 4 nos.
USFD machine 1 no.
Angle Grinding machines 60 nos.
Riveting equipment's 3 sets
Automated I-girder Assembler 1 nos.
Automated I-girder Straightener 1 nos.
CNC Gas Cutting Machine 1 nos.
End Milling Machine 1 nos.
Calibrated Inver Tape 1 nos.
Measuring Instruments/Gauges As required
Safety equipment's
As required

25.  Study shop drawings & make cutting plan
 Prepare Steel Indent/obtain from BBJ
 Send Requisition to HO for P.O.
 Pursue SAIL for supply of steel
 Coordinate with SAIL Patna & Fatuha Yard
 Authorized Agency to lift steel from Yard
 Unloading & Stacking at Yard
Contd….

26.  Identification & Correlation with MTC
 Visual Inspection & Dimension check
 Verification of product analysis in MTC
 Joint Sampling for Testing at NABL lab
 Verification of Physical & chemical properties
 Verification of Charpy V Notch Impact Test
 Review of Test Results by Railways
 Acceptance by BBJ/Railways.

27.  Commissioning of plants/equipments
 Transport steel from GIL Yard to BBJ Yard
 Make copy of Master Jigs/Fixtures
 Transport Jigs/Fixtures back to GIL Yard
 Prepare Lay Out & check with Jigs
 Issue steel to P&R based on cutting plan
 Prepare Templates for cutting of Plates
 Proceed with fabrication as per flowchart

28. Broad Classification of Fabricated items
Built-up Sections Requiring Welding (62%)
 Top Chord, Bottom Chord, End Raker : Box Section
 Diagonals & Verticals : Channel Type Box; I-Section
 Cross Girders, Stringers, Hangers : I-Section
Not Requiring Welding (38%)
 Gusset/Splice/Pack Plates – Plates
 Bracings, cleat angle & other Misc items – Angles
 Bent Gusset/Splice Plates – Plates + Bending

29. FLOWCHART FOR GUSSET/SPLICE PLATES
Issue of
Steel
Cutting
Plan
Marking Grinding
Cutting
Check for Straightness
Straightening
Tack with Jig
Finishing
Grinding
Remove JigDrilling
Sandblasting/
Metalizing/Paint
APPROVAL BY RDSO

30. FLOWCHART FOR BUILT-UP SECTIONS
Issue of
Steel
Cutting
Plan
Marking Grinding
Cutting
Check for Straightness
Straightening
Fit Up &
Tack Weld
Finishing
Grinding
Remove Jig
Place Job on
Fixture
Sandblasting/
Metalizing/Paint
APPROVAL BY RDSO
Tack with Jig Drilling
End Milling
SAW
Welding
Straightness check
Straightening

33.  Challenges
 Avoid distortion during cutting/welding
 Grinding of cut edges of thick HT Plates
 Straightening during Fit up & welding
 SAW Welding inside box sections
 End Milling of Chord members
 Accuracy of drilling holes
 Achieve Camber

36.  Cantilever erection as per Scheme by BBJ
 Involves two customized derrick cranes – 1st
for forward erection and 2nd for follow up
work
 Some members are strengthened to cater for
the erection stresses.
 First span (between P30 – P29) will be erected
conventionally on trestle supports at all nodes
 Once the camber & alignment is accepted,
cantilevering of further spans starts.
 Feeding of fabricated components will be by
trolley at rail level

37. Contd…..

40.  High Tensile Rivets 24mm dia used at Site Joints
 Rivets replace temporary fasteners (bolts/drifts)
 A typical Riveting gang consists of five men
 All holes in the joint to be made fair
 Rivets comprise about 1.5% of the Span weight
 Equipments used
 Compressor – Operates the forge, hammer, dolley
 Forge – Used to heat the rivet by pearl hard coke
 Tongue – Used to handle red hot rivets
 Hammer – Used to hammer and prepare rivet head
 Dolley – Used to hold rivet in position

41.  Important to control cantilever erection
 To start after erection of 3 - 4 spans
 Involves
Jacking of entire span on Traversing base
Ensure Vertical & Horizontal Alignment
Lowering on Bearings
 Followed by grouting of Bearings
 Equipments used
 Hydraulic Jacks – 500 T Cap – 9 nos
 Hydraulic Traversing Base – 9 nos
 Pack plates – As required

42.  Repeated handling of long heavy structural
 Sandblasting area close to residential area
 Access, staging & walkways on bridge
 Riveting platforms on bridge
 Jacking of spans
 Weather Condition during cantilevering
 1st Span erection on river bed

44. DESCRIPTION AS PER TENDER AS PER LATEST CE
CONTRACT VALUE
a) WORK DONE 375.18 376.29
b) ESCALATION - 74.31
c) OTHERS - 0.97
d) TOTAL 375.18 451.57
B. S. EXPENDITURE 269.55 290.50
Y.S. EXPENDITURE 47.20 48.72
B.S. + Y.S. 316.75 339.22
PLANT HIRE CHARGES 6.80 6.93
B.S. + Y.S. + PLANT HIRE CHARGES 323.55 346.15
H.O. OVERHEADS 6.06 9.57
FINANCE CHARGES FOR –VE CASHFLOW 11.26
CONTINGENCIES 3.40 1.61
TOTAL EXPENDITURE 344.27 357.33
MARGINS 30.91 94.24

45. THANK YOU