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GAMMON INDIA LIMITED

SUMMER INTERNSHIP

AT

THE NEW BRAHMAPUTRA BRIDGE

By,

Ms. Baishali Choudhury

Mr. Jehinder Singh

Mr. Preetam Banerjee

Mr. Angshuman M. Saharia

Mr. P. Jarken Bui

Mr. Azaz Ahmed

B.TECH ( 4th sem.)

Tezpur University

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ACKNOWLEDGEMENT

We feel extremely satisfied presenting the report on the completion of the summer trainingprogram at GAMMON INDIA LIMITED from 7th June’2011 to 25th June’2011, for constructionof the NEW BRAHMAPUTRA BRIDGE PROJECT at Guwahati on NH-31, ContractPackage-EW-II (AS 28).

Expressing our heart full thanks and gratitude to GAMMON INDIA LIMITED, who has giventhis great opportunity and encouraged us to develop and expertise our knowledge, technicalskills etc.

The valuable time and support extended to us by the staff of GAMMON INDIA LIMITED, Mr.A.N.SINGH (Sr. Project Manager), Mr. D.K.DAS, Mr. S.CHARKRABORTY, Mr. R.K.VERMA,Mr. S. DUTTA, Mr. P.K.CHANDA, Mr. PAWAN, Mr. VISHAL and other engineers, technicaland non-technical stuff helped us to learn a lot of new things and we are extremely grateful.

Also we are great full to Associate Professor Atanu Kr.Dutta, HOD- Department of CivilEngineering, Tezpur University for being positive regarding the training program.

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INDEX

TOPIC Page no.

INTRODUCTION 1

CONTRACT 2

WELL FOUNDATION 3

HIGHWAY 4

SUPERSTRUCTURES 5

QUARRY 6

STORE 7

PLANNING AND BILLING 8

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INTRODUCTION

In order to reduce traffic congestion on NH 31 (Near Guwahati, Assam), the NHAI (NationalHighway Authority of India) had decided to construct a new three lane bridge named NewBrahmaputra bridge running parallel to the existing two lane bridge- The Saraighat.

PROJECT: Construction of New Brahmaputra Bridgeon NH 31, near the city of Guwahati,Assam. Contract package no. EW-(AS-28)

CLIENT: National Highway Authority of India(NHAI), G5 & G6, sector-10, Dwarka, NewDelhi -110075.

CONSULTANT: Mott McDonald Private Ltd, A-20, Sector -2, Noida, Uttar Pradesh.

DESIGN CONSULTANT: Span Consultant Private Ltd, Span House,Gurudwara Road, Madangir, New Delhi-110062.

CONTRACTOR: M/s Gammon India Ltd, Gammon house,Veer Savarkar marg, Prabhadevi,Mumbai-400025.

PROOF CONSULTANT: IIT, Delhi

CONTRACT VALUE: Rs. 238.34 crores only

LOCATION OF BRIDGE: 26⁰10’45” N, 91⁰45’0” E in the District ofKamrup, 40 m d/s of the existingSaraighat bridge.

SALIENT FEATURES OF THE PROJECT:

Contract package: EW-II (AS-28)

Contract period: 42 Month

Contract value: Rs. 238,44,25,881

Date of Agreement: 4th August, 2006

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Date of commencement: 22nd October, 2006

Date of completion: 21st April, 2010

Defect liability period: 365 days after completion

Retention money: 6% of contract price

Date of receipt of main bridge drawing: 8th May, 2007

Extension of time: Up to 30th November, 2012

RIVER BRAHMAPUTRA:

Nature of bed soil: Alluvial.

Flow: Perennial, high flood during monsoons.

Nature of the catchment: Partly plain, mostly hilly.

High flood level: 49.88m

Lowest flood level: 29.696m

Maximum stream velocity: 5m/s

Maximum stream discharge: 72400m3/s

Mean annual discharge: 46400m3/s

MAIN BRIDGE:

Road level of the main bridge: 69.072m

Length of main bridge: 1493.584m

Foundation type: Double ‘D’ type.

No. of well: 11 no.s

Size of well: 16m X 10m

Depth of well: 48.400m (Average)

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Thickness of well staining: 2.5m

Thickness of false staining: 0.5m

Size of well cap: 16m X 10m X 3m

Pier type: Tapered hollow pier

Size of pier cap: 12m X 8.5 X 4m

Total width of main bridge deck: 13.875m

APPROACHES/VIADUCTS:

Chainage in scope:

Amingaon side: 1121+850 to 1121+241

Guwahati side: 1123+490 to 1123+600

Foundation type: Cast in situ RCC vertical bored pile.

Diameter of pile: 1200mm

Depth of pile: Average of 25m

Substructure: RCC piers.

Size: 7m X 1.35m

Height: 3.8m to 5m

Viaduct length: 75+75+105m

Total no of spans: 10 no.s

ROAD WORK:

Length: 2087m

Carriage way: 11m + 11m

Retaining wall: 1600RM

Toe wall: 608.873RM

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Slip road: 2 X 1245RM

SEISMIC ZONE:

The project lies in zone-5 of seismic activity as per IRC-6. As such Gammon India Ltd haddesigned the bridged wherein a new technology is used. ‘Shock Transmission Units (STU)’are placed below the bridge at certain intervals which will resist any seismic force.

CLIMATE:

The annual rainfall in the Brahmaputra valley varies between 30⁰ to 34⁰ during summer and8⁰ to 12⁰ during winter. The humidity varies from 69% during January-February, to 80%during monsoons.

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CONTRACT

Contract defines the terms and conditions under which the employer and the contractor isbound into an agreement.

It includes specifications, drawings, bill of quantities, the tender, the letter of acceptance, thecontract agreement and other such related documents which may be incorporated in theletter of acceptance or the contract agreement.

Overall, it is divided into 4 parts as given below-

Part 1 of 4:

1. Contract agreement.2. Power of attorney.3. Letter of acceptance.4. Copy of bank guarantee along with confirmation letter.5. Invitation of bid.6. Instruction to bidders with classification of bidder.7. General conditions of the contract.8. Condition for particular application.9. Appendix to bid.10. Priced bill or quantity, standard form and schedule.

Part 2 of 4:

Technical Specifications.

Part 3 of 4:

Drawings

Part 4 of 4:

Technical bid

A brief summary of some of the documents:

AGREEMENT:

The Agreement was made on 4th of August, 2006 between NHAI (Employer), Plot No. G5 &G6, sector 10 dwarka, New Delhi and M/s Gammon India Ltd (Contractor), Gammon House,Veer Savarkar marg, Prabhadevi, Mumbai.

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POWER OF ATTORNEY:

Mr. Bhole, General Manager, Work survey was nominated by Gammon India Ltd to be theirtrue and lawful attorney for them in their name and on their behalf to accept the letter ofacceptance and to sign and execute the contract agreement between NHAI and GammonIndia Ltd.

LETTER OF ACCEPTANCE:

It states that Gammon India Ltd’s bid for contruction of new Brahmaputra Bridge nearGuwahati on NH 31 in the state of Assam, their civil package no. EW-II (AS-28) is accepted.

PERFORMANCE SECURITY:

Performance security to NHAI on behalf of Gammon India for the project is provided byCanara Bank.

Canara bank’s guarantee no. 06BG1002, dated 20/06/2006 for Rs 23,84,00,000/- is issuedin favor of NHAI on behalf of Gammon India Ltd.

INVITATION FOR BID:

Includes Bid document.

QUALIFICATION OF BIDDERS:

In order to qualify the bidders shall-

1. Submit power of Attorney.2. Adequate experience of work.3. Financial capacity.4. Technical capacity5. Current contract commitment6. Annual audited turnover and financial data.7. Submit proposed methodology in sufficient detail and the program of

construction backed with equipment planning and deployment duly supportedby output calculation and quality assurance.

BIDDING DOCUMENT:

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Vol. 1 – Set 1

1. Instruction to Bidders.2. General conditions of Contract- part 1.3. Conditions of particular applications- part 2.

Vol. 2

Technical Specifications

Vol. 3

1. Form of Bid and Appendix.2. Bill of Quantity.3. Form of bill security.4. Schedule of supplementary information.5. Sample forms for qualification.

Vol. 4

Drawing

Vol. 5

Documents to be furnished by the bidder.

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FOUNDATIONS

Foundation types for the New Brahmaputra bridge:

1. A-1, P-1 – P-6 and P-18 – P-21, A2 - Pile foundations2. P-7 – P -17 - Well foundation

WELL FOUNDATIONS:

DOUBLE D WELL FOUNDATION:

In this type of well foundation, the dredge hole is in the form of a D-shape. It consists of 2 D-shaped dredge holes, therefore it is called double –D well foundations.

CHARACTERISTICS:

1. It is mostly used for the piers and abutments of bridges which are too long to beaccommodated on circular well.

2. It provides lateral stability.3. It has simple shape and easy to sink but requires greater effort than circular well.4. Staining is relatively thick .5. It is more prone to tilt and shift due to unsymmetrical shape and possible unequal

dredging.

Fig: Diagram showing parts of well foundation

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PARTS OF THE WELL:

1. CUTTING EDGE: It is the lower most tapering edge of the well made of steel whichfacilitates cutting through soil for the sinking of the well.

2. WELL CURB: The cutting edge has to be strengthened suitably to take up the heavyloading and this portion is called the well curb. It is usually made of heavily reinforcedrich concrete.

Fig: Cutting edge

3. STAINING: The well staining is the main body of the well which transfers load to freesub-soil. It also acts as a cofferdam during sinking and provides the weight forsinking.

4. BOTTOM PLUG: The bottom of the well is mass concreted to prevent further sinkingof the well in future and is known as the bottom plug. It is done by means of pipesinserted through the D’s of the well. After mass concreting the plug is tested forcracks.

5. REINFORCEMENT: It provides required strength to the structure during sinking andservice.

6. WELL CAP: The well cap is a R.C.C slab laid at the top of the well staining and isusually cast monolithically with the staining. It transmits the load of the superstructureto the staining.

CAISSONS:

Caisson is a box-like structure usually round or rectangular which is sunk from the surface ofeither land or water to some desired depth. It is pre-cast at the bank with the bottom which isgenerally provided with opening which are plugged and toed to the required positions bytugs and then plugs are removed to permit the caisson to reach the bottom of the river bed.

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After the caisson rests in its final position, concrete blocks are normally dumped in to thehollow portion to increase its lateral stability.

COMPONENTS OF CAISSONS:

1. Cutting edge2. A-frame3. B-frame4. Extension

CONSTRUCTION OF ISLANDS:

An island, if necessary, is constructed enclosing the construction site to facilitate theconstruction of the well foundation in dry condition, if depth of water is not more than 4.5 to6.0 m. In case, where the velocity of water in the river is sufficiently high making it difficult toconstruct either an island or cofferdam to construct a well, caisson type construction hasbeen used.

SITE: P-7, P-8, P-9 ,P-16 and P-17 are planned to be constructed using islands.

Fig: Island for pitching the well curb

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Fig: An island for pitching a well curb

Fig: Well sinking using crane and grab

TILT:

Tilt is the angle by which the central axis ( both X and Y ) of the well gets rotated. Maximumtilt allowed is 1:80.

CALCULATION OF TILT-

1) R.L of the points are taken on all 4 sides using total station.2) For e.g. => G/s = 20.170

A/s = 20.120D/s = 20.100U/s = 20.150

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TILT IS CALCULATED USING THE FOLLOWING FORMULA:

TILT = difference in RL / length

Thus, tilt along X-X = 1 : 200 Amingaon side

tilt along Y-Y = 1 : 320 downstream side

SHIFT DUE TO TILT = diff in RL * height of well / length

Thus ,shift => X-X = 100 mm Amingaon side

Y-Y = 62.5 mm downstream side

SITE VISIT:

The dredging process was going on in P-12 by means of a crane and a grab.

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HIGHWAY

In the planning for New Brahmaputra Bridge Project, highway is provided measuring 700m inAmingaon side and 1200m along the Guwahati side with retaining walls measuring 3.8m -5m in height. The highway is designed to be of flexible pavement with 3 lanes for smoothmovement of the traffic. Moreover it is designed to manage a volume of traffic 3 times thanthat of today’s.

While designing and constructing the highway IRC recommended CBR values, frictionalcoefficient, etc. are considered. The flexible pavement highway involves the distancebetween the viaduct of the bridge and the point where it joins the existing highway.

LAYERS OF FLEXIBLE PAVEMENT:

Fig: layers of flexible pavement

SPECIFICATIONS AND DETAILS

LENGTH OF HIGHWAY

Amingaon side : 700m

Guwahati side : 1200m

HEIGHT OF RETAINING WALL: 3.8m - 5 m

COST OF HIGHWAY PROJECT: 130 cr

PROJECT COMPLETION TIME: DECEMBER, 2012 (conditions apply)

The materials used in embankment, subgrades, earthen shoulders and miscellaneousbackfills shall be soil, moorum, gravel, sand, excavated material.

CONSTRUCTION OPERATION

1. Compacting ground supporting embankment/ subgrade

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2. Compaction: Vibratory roller of not less than 100 KN weight with plain or pad footdrum or pneumatic roller of 300 KN static weight shall be used for compaction.

Subgrade strength: The subgrade should have a minimum design CBR value of 5%

MATERIALS

Cement for use shall comply with the requirement of IS : 269, 455, 1489 or 8112.

Water to be used shall be clean and free from injurious salts

WEATHER LIMITATIONS:

Cement soil construction shall not be done when the air temperature in the shade is lessthan 10⁰C.

The soil before addition of cement shall be pulverized

IS SIEVEMINIMUM % BY WEIGHT PASSING THE IS SIEVE

26.5 mm 100

5.6 mm 80

Moisture content for compaction: The mix shall be compacted at OMC or not more than +2%of OMC

ROLLING:

Compaction of mix is completed within two hours of its mixing

CURING:

The subgrade shall be suitably cured preferably for 7 days but at least min. of 3 days bysprinkling water in every 4 hours.

STRENGTH:

Soaked CBR after 7 days at density shall not be less than 10% in laboratory.

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Surface finish and quality control of works, arrangement of traffic, measurement of payment,soil erosion and sedimentation control.

TEST FOR BITUMINOUS CONSTRUCTIONS

Dense bituminous macadam/ semi dense bituminous concrete/ bituminous concrete

1. Sand equivalent test2. Polished stone value (PSV)3. Density of compacted layer.

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SUPERSTRUCTURE

A superstructure is an upward extension of an existing structure above a baseline. The bridge deck is to be constructed by the cast in situ Cantilever Segmental

Construction method. Formwork for the in situ cast parts shall be made by steel.

PCC: The mixture of cement, sand and aggregate is called Plain Cement Concrete (PCC).

PRE-SRTESSED CONCRETE:

Pre-stressed Concrete is a method for overcoming concrete’s natural weakness in tension. Itcan use to produce longer span in bridges than is practical with ordinary reinforced concrete.

Pre-stressing tendons (high tensile steel cable or rods) are used to provide a clamping loadwhich produces a compressive stress that balances the tensile stress that the concretecompression member would otherwise experience due to bending load.

PIER:

A pier is a raised structure, including bridge and building supports and walkways, over water,typically supported by widely spread piles or pillars. Piers can range in size and complexityfrom a simple light-weight wooden structure to major structures extended over a mile out tosea.

PIER CAP:

Pier Caps are designed to be placed on top of pillars or columns. They protect brick or stonework from weather and corrosion and add beauty to the work. They usually needed to beslightly larger than the dimensions of the pillar itself so that they overhang.

BOX GIRDER:

A box girder or Tubular girder is a girder that forms an enclosed tube with multiple walls,rather than I or H-beam. The advantage of a box girder is that it better resists torsion. Havingmultiple vertical webs, it can also carry more load than an I beam of equal height.

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DETAILS OF SUPERSTRUCTURE OF MAIN BRIDGE (P7 to P17):

Sl.No.

Location Part of Structure Height of Structure(m)

1 P-7 Pier 7.312 Pier Cap 43 P-8 Pier 16.314 Pier Cap 45 P-9 Pier 17.816 Pier Cap 47 P-10 Pier 17.818 Pier Cap 49 P-11 Pier 17.8110 Pier Cap 411 P-12 Pier 17.8112 Pier Cap 413 P-13 Pier 17.8114 Pier Cap 415 P-14 Pier 17.8116 Pier Cap 417 P-15 Pier 10.3118 Pier Cap 419 P-16 Pier 10.3120 Pier Cap 421 P-17 Pier 322 Pier Cap 4

Fig: P-17

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QUARRY

A quarry is a type of open-pit mine from which rock or minerals are extracted. Quarries aregenerally used for extracting building materials such as dimension stone, constructionaggregate, sand and gravel.

Fig: Quarry

BATCHING PLANT:

The process of weighing out or measuring out the ingredients for a batch of concrete iscalled batching. In this plant mixing is done by machine, the size of the batch depends uponthe rated capacity of the mixer.

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Fig: Batching Plant

AGGREGATES USED:

10mm and 20mm.

BASIS OF MIXING:

Mixing is done by Transit mixer. They are truck mounted having a capacity of 6m3. Mixedconcrete is transported to site by keeping it agitated all along at a speed varying between 2to 6 rpm

.

Fig: Transit Mixer

ADMIXTURES USED:

1. Eastern Setcrete- Waterproofing Admixture2. SWC3. BASF-Superplasticizer

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IS CODES:

Following IS codes are followed

1. Cement (general)- IS-40312. OPC 53 grade cement- IS-122693. OPC 43 grade cement- IS-81124. Concrete mix- IS-102625. Coarse and Fine aggregate-IS-383

EXPERIMENTS:

1. Cube testing 7th day2. Cube testing 28th day3. Concreting4. Cement Cube testing5. Aggregate testing

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The tests for concrete have done at 150 mm cube to determine the compressive strength inN/mm2.

MACHINES USED:

1. Aggregate Crushing Machine2. UTM (Universal Testing Machine): 2000kN (limit).3. Aggregate Impact Value Apparatus.4. Set of Sieves.5. Thickness Gauge (for determination of Flakiness index)

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STORE

The efficient handling and storing of materials are vital to industry. In addition to rawmaterials, these operations provide a continuous flow of parts and assemblies through theworkplace and ensure that the materials are available when needed. The improper handlingand storing of materials often result in costly injuries. Its main purpose is for housekeeping ofmaterials, issuing of materials and check on the availability of materials.

MAIN STORE:

Main store is used for storage and efficient distribution of materials. It contains all sort ofmaterials required for construction like diesel, petrol, hydraulic oil, TMT bars, ropes,hammers, nuts, bolts steel, iron, machine parts, tyres, welding equipments etc and includingsafety equipments like safety helmets, safety nets etc.

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PLANNING AND BILLING

Planning involves optimal utilization of all the available resources for maximum output. It’sthe prime requisite for any project to proceed. It aims to achieve a desirable target in a costeffective way and at scheduled time.

Following reports are made and maintained by the planning department:

1. Daily Progress Report or the DPR.2. Bridge Progress Report (Weekly).3. Monthly turnover.4. Day to day program for next month (Monthly).5. Standard deviation (Monthly).6. R.A. bill (Monthly).7. Reconciliation statement (Monthly).8. Client billing and collection statement (Monthly).9. Safety report (Monthly)10. Monthly Progress Report.11. Weekly Progress Report.

The reports are made under the supervision of the planning head, and are sent to the HeadOffice and Project manager.

QUALITY ASSURANCE PLAN:

Provides a systematic approach to managers, engineers and supervisory staff connectedwith the project for correct implementation of the project specifications and codes as well asapplication of sound engineering practices so as to minimise human errors and enslavesstability, soundness and durability.

WORK ORDER:

It comes under module execution & sub contractor of ERP which deals with the variousdetails of the job as well as the involved costs.

ITEN RECEIPT NOTE or the IRN:

IRN contains info regarding costs, quality, quantity, source and testing criteria.

CONTROL ESTIMATE:

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It is prepared for providing a skeletal plan incorporating the changes after the tenderingstage till date, based on the inputs received from the project site. It attempts a plan tomonitor overall progress, turnover and expenditure at site and at the corporate office level. Itincludes all the monetary aspects of the project like inflation.

TURNOVER:

It is the total money involved in the project including escalation as well as the total workdone.

INTERIM PAYMENT CERTIFICATE:

Interim payment certificate or the IPC is similar to a running account bill and is the bill givento the client for claiming money after a certain amount of work done at certain period of timeas specified in the BOQ is completed. In includes the calculation of escalation etc.

PRICE ADJUSTMENT:

It gives the difference in the base price index (BPI) and the current price index (CPI). Priceadjustment is done for increase in labour, materials, fuels and lubricants in accordance withcertain formulae.

MOBILIZATION ADVANCE:

It is the sum of money given by the client- NHAI to the contractor- Gammon India Ltd formobilization and utilization of resources at a rate of interest. The contractor can decidewhether it requires the advance or not.

RETENTION MONEY:

IT is the amount deposited by the contractor (Gammon India Ltd) to the employer (NHAI) asa security deposit.

LIQUIDATED DAMAGES:

It is the amount the contractor (Gammon India Ltd) is liable to pay the client (NHAI) for delayin the project completion.

DEFECT LIABILITY PERIOD:

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It is the guarantee period which mentions that the contractor is liable to rectify and maintainthe job, from the date of handling over of the works.

ENTERPRISE RESOURCE PLANNING (ERP):

It is an automated management information system having different modules through whichthe database of all the records related to the project is managed. The main server is locatedat Head Office, Mumbai.

The modules of ERP are as:

1. Accounts.2. Client Billing.3. Control Estimate.4. International Standardization of Organization (ISO).5. Planning.

BILL OF QUANTITIES (BOQ):

It is the total quantity of work done under the project as given in the tender without theinclusion of costs. The rates of the various items in the BOQ are finalized by the companyduring the time of tender estimation.