Internship Report Bharat PDF

8/10/2019 Internship Report Bharat PDF

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Summer Internship at Wazirabad Bridge Project

(Signature Bridge)

Department of Civil Engineering

Indian Institute of Technology (IIT) Delhi

Hauz Khas, New Delhi - 110 016.

Submitted by:

Bharat Mittal

Entry No.: 2011CE10342

Group No.: 2

Date: 25 th August, 2014


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Contents

1. Introduction

2. Project Brief

3. Brief Information about Main Cable Stay Bridge

4. Approaches

5. Present Status

6. Specialized Works for Main Bridge

7. Conclusion

8. References


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1. Introduction

Signature bridge project is state of the art project of DTTDC (Delhi Tourism & Transport

Development Corporation) to construct a magnificent bridge in the National Capital Territory

Delhi. The cable-stayed bridge will link NH -1 near existing T- point at Wazirabad on western

bank and Bund road at Khajuri Khas on Eastern Bank of Yamuna River, thus connecting North

Delhi with East Delhi.

A need was felt to make a bridge because of the unprecedented increase in population in west and

east Delhi and thus resulting in the frequent traffic jams especially during peak hours. But it was

decided to not only make any bridge but to make a Signature Bridge since Delhi doesnt have

any modern structure as a landmark among world class cities. Also, to facilitate the movement of

vehicular traffic new express lanes will be constructed to connect Ring Road with the bridge.

Equipped with eight lanes, this engineering masterpiece will have 1.2 meter wide central verge,

space for anchoring cables, maintenance walkway and crash barrier on either side of the central

verge. The deck will be composite (steel and concrete) while pylon will be in steel.

Signature Bridge is to be made with water recreational facilities in Yamuna water and to attract

tourist attraction. For making it a tourists spot there are several specialized works proposed for the

main bridge. These include light illumination of the pylon, bridge and flyovers. Also special

lighting effects will be provided at special occasions like Independence Day, Republic Day etc.

There is a provision of making inclined lifts within the pylon which will add to its beauty.

So, we can say that this bridge will be State of the Art Bridge and will truly give Delhi a much

required infrastructural landmark.


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Figure 1: Perspective View of Signature Bridge

2. Project Brief

It is a Government of Delhi Project being executed by DTTDC as Deposit Work.

Project Cost Rs 1131 Cr Partially Funded under JNNURM Rs 380.6 Cr Date of Commencement (Approaches) June 2008 Target Date of Completion (Approaches) June 2014 Date of Commencement (Main Bridge) March 2010 Target Date of Completion (Main Bridge) Sep 2015


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2.1 Project Consultants

Bridge Approaches

Preliminary Design M/s Stup Consultants Pvt Ltd M/s Stup Consultants Pvt Ltd

Main Design

Consultant

M/s Schlaich Bergermann &

Patners, Germany

M/s Tandon Consultants Pvt

Ltd (TCPL)

Associates to Main

Consultant

M/s Construma Consultancy Pvt

Ltd (CCPL)

M/s L R Kadiyali

M/s Archom

Proof Consultant JV of M/s Systra, France MichelVirlogeux

M/s Construma ConsultancyPvt Ltd (CCPL)

Associates to Proof

Consultant

M/s Tandon Consultants Pvt Ltd

(TCPL)

Soil investigation M/s Cengers Pvt Ltd

Table 1: Project Consultants

2.2 Project Components

The project is mainly divided into 2 parts:

1. Bridge

2. Approaches

Approaches are further divided in

a) Western approach

b) Eastern approach


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2.3 Key Plan

Figure 2: Key Plan of Signature Bridge

Figure 3: Plan of Signature Bridge


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2.4 Project Phases

This project is to be done in 2 phases:

1. Develop Architectural and Engineering Monument

2. Develop Tourism Destination Infrastructure

3. Brief information about Main Cable Stay Bridge

Contract Value Rs. 631.81 Cr. Work Awarded March 2010 Duration of Work 45 Months Target For Completion Sep 2015 Contractor : JV of Gammon(India) Construtora-Cidade (Brazil) Tensacciai (Italy)

3.1 Salient Features of Main Cable Stay Bridge

Bridge Length : 575m+ 100m West extension No. of Lanes : 2 x 4 Lanes + 2 Service Lanes Width of Carriage Way : 35.2m

o Carriageway : 14m (Either side)o Central Verge : 1.2m

o Service Lanes : 2.5m (Either side)

3.2 Technical Features of the Main Bridge

3.2.1 Cable Stayed Deck

Front Cables - 15 Pairs Back Stays - 4 Pairs

3.2.2 Pylon

Bow Shaped Asymmetric Structure 154m High Steel Structure (Double the Height of Qutub Minar)


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3.2.3 Main Span 251m

3.2.4 Approach Spans 9nos @ 36m

3.2.5 Deck

Steel- Concrete Composite Plate Girders up to 2.3m depth RCC Precast / Cast in-situ Deck 250 to 700mm thick

3.2.6 High Tensile Grade Steel Plate

S355J2+N/NL S460J2+NL

Z+ Quality

3.2.7 Steel Plate Thickness 20mm to 250mm

3.2.8 Foundations

Figure 4: Foundations of the Pillars


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3.2.9 Spherical Bearings

Main Pylon Bearings : 17500 Ton Load Capacity Bearing on Secondary Spans : 500 to 1600 Ton

3.2.10 Pendulum Bearing

Backstay Cable Anchoring with Foundations

3.2.11 Expansion Joint

Modular Strip Box Longitudinal Movement +/- 350/200/100mm

4. Approaches

Contract Amount Rs. 348.9 Cr. Commencement of Work June 2008 Duration of Work 42 Months Schedule Completion December 2011 Target Completion June 2014 Contractor Gammon India Ltd.

4.1 Geometric Features of the Approaches

No. of Lanes on Main Flyovers 3+3 Lanes No. of Lanes on Loops/Ramps 2/3 Lanes No. of Lanes on Lower level loops 2 Lanes + Cycle trek Width of Carriage Way

o Main Flyover Carriageway 11+11mo Central Verge 1.2m

o Loops/Ramps Carriageway 9.0mo Cycle Trek 2.5m


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4.2 Western Approach

Figure 5: Western Approach

4.2.1 Geometrical Features

Multilevel Grade Separator along Outer Ring Road at Wazirabad Cover 3 Intersections Components

o 1.8 km Long Main Flyover along Ring Road Integrating 3 Intersections

o 8 nos Loops & Ramps for Right & Left Turning Traffic, Connecting to Main Bridge


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4.2.2 Segment Erection

Precast pre-stressed segmental superstructures are designed and attached in-situ monolithically to

the piers.

Figure 6: Precast Segmental Via-ducts with Ribs

4.2.3 RE Wall

Retaining walls are built in order to hold back earth which would otherwise move downwards.

Their purpose is to stabilize slopes and provide useful areas at different elevations, e.g. terraces

for agriculture, buildings, roads and railways.


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RE wall panels are pre-casted in casting yard. Stirrups are connected to these panels to produce

friction force from sand and keep the structure stable.

The RE wall contains a facia made up of concrete panels, concrete blocks or sometimes geotextile.

After certain interval the earth to be retained is reinforced with either metal strips, metal bars or

geogrids. The retention of the soil is derived from friction between the reinforcement and the soil.

The C (cohesion) and phi (angle of internal friction) of the soil play very important role.

The main advantage of RE wall is that it does not require any foundation and thus can be built

easily where there is a constraint of working space viz. in the midst of cities. It is also found that

when the height of retaining wall increases more than 3m the RE walls are more economical.

Though views differ on this. The major disadvantage is that it takes a lot of time in construction

and a lot of pre erection planning and execution is required.

4.2.4 Crash barrier Crash Barrier is designed to restrain vehicles from crashing off the side of a bridge and falling onto

the roadway, river or railroad below. It is usually higher than roadside barrier, to prevent trucks,

buses, pedestrians and cyclists from vaulting or rolling over the barrier and falling over the side of

the structure.

4.2.5 Pre-stressing

Pre-stressed concrete is a method for overcoming concrete's natural weakness in tension. It can be

used to produce beams, floors or bridges with a longer span than is practical with ordinary

reinforced concrete. Pre-stressing tendons (generally of high tensile steel cable or rods) are used

to provide a clamping load which produces a compressive stress that balances the tensile stress

that the concrete compression member would otherwise experience due to a bending load.

Pre-stressing of concrete may be achieved by either pre-tensioning high tensile steel strands before

the concrete has set, or by post-tensioning the strands after the concrete has set.

Pre-tensioning is the application, before casting, of a tensile force to high tensile steel tendons

around which the concrete is to be cast. When the placed concrete has developed sufficientcompressive strength a compressive force is imparted to it by releasing the tendons, so that the

concrete member is in a permanent state of pre-stress.

Post-tensioning is used in the construction of various bridges. Post-tensioned concrete is the

descriptive term for a method of applying compression after pouring concrete and the curing


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process (in situ). The concrete is cast around a plastic curved duct, to follow the area where

otherwise tension would occur in the concrete element. A set of tendons are fished through the

duct and the concrete is poured. Once the concrete has hardened, the tendons are tensioned by

hydraulic jacks that react (push) against the concrete member itself. When the tendons have

stretched sufficiently, according to the design specifications, they are wedged in position and

maintain tension after the jacks are removed, transferring pressure to the concrete. The duct is then

grouted to protect the tendons from corrosion.

This method is commonly used to create monolithic slabs for house construction in locations where

expansive soils (such as adobe clay) create problems for the typical perimeter foundation. All

stresses from seasonal expansion and contraction of the underlying soil are taken into the entire

tensioned slab, which supports the building without significant flexure.

After stressing of segments two activities follows:1. Water treatment - It is done to check the presence of air voids inside the segments which may

corrode the HYSD bars used for stressing.

2. Grouting - The purpose of grouting the cable is to provide permanent protection to the post

tensioned steel against corrosion and develop bond between pre-stressed steel and surrounding

concrete. The grout ensures encasement of steel for corrosion protection and fills the duct space to

prevent water/air passage. We mix water & cement in ratio 0.4:1. This is done to prevent corrosion

of strand wires.


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Figure 7: Some Ongoing Activities at Western Approach

4.3 Eastern Approach

Figure 8: Eastern Approach


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4.3.1 Geometric Features A 1.8 km long and up-to 10m high embankment

Ground Level Rotary on high embankment (120m diameter)

A 850m long flyover at Khajuri Khas Intersection

Guide Bunds, Launching Apron & Slope Protection Works

4.3.2 Well Foundation

It is suitable for deep water where it is difficult to carry construction equipments suitable for

river bed, alluvial soil which mainly consists of sandy.

4 bench marks are provided on every quarter of well so as to notice tilting and shifting of the

well.

Figure 9: Drawing of Well Foundation ( source: http://3.bp.blogspot.com/-u-

TEyXuGPbA/UdwY1IW3d6I/AAAAAAAAAPc/1doVK3WCl3Q/s1600/Picture1.gif )


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4.3.2.1 Components of Well Foundation

1. Well Cap

It is a RCC slab laid on top of the wall staining and is usually cast monolithically with

staining Transmit the load of superstructure to the staining

2. Steining Wall

It is the main body of well which transfers load to the subsoil Acts as a cofferdam during sinking and provides weight for the sinking

3. Well Curb

The lower wedge-shaped portion of well staining is called the well curb Facilitates the process of sinking

4. Cutting Edge The lower most portion of the well curb is the cutting edge It cuts into the soil during sinking

5. Bottom Plug

After the well is sunk to the required depth, the base of well is plugged with concrete. This

is called bottom plug

Transmits the load to the subsoil

The bottom plug shall be provided in all wells and the top shall be kept not lower than 300mm in the centre above the top of the curb

Height of sump should be 150mm to permit easy flow of concrete through tremie to fill up

all cavities

Concrete shall be laid in one continuous operation till the dredge hole is filled to the

required height

For under water concrete, the concrete shall be placed by tremie under still water condition

and the cement content of the mix be increased by 10 percent

6. Sand Filling

Sand filling shall commence after a period of 14 days of laying of bottom plug. Also, the

height of the bottom plug shall be verified before starting sand filling

Sand shall be clean and free from earth, clay clods, roots, boulders, shingles, etc. and shall

be compacted as directed. Sand filling shall be carried out up to the level shown on the


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drawing or as directed by the Engineer

7. Dredge Hole

The well is sunk by excavating soil from within the well. The hole formed due to the

excavation of soil is called the dredge hole

It is latter filled with sand This sand filling helps in distributing the load of superstructure to the bottom plug

8. Top Plug

It is a concrete plug covering the sand filling usually constructed on top It provides contact between the well cap and sand filling Helps in transferring the load through the sand filling A 300 mm. thick plug of cement concrete shall be provided over the filling

9. Well Cap A reinforced cement concrete well cap will be provided over the top of the steining in

accordance with the drawing

Concreting shall be carried out in dry condition A properly designed false steining may be provided where possible to ensure that the well

cap is laid in dry condition

Figure 10: Ongoing Construction of Well foundation


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Sinking

It occurs in two parts:

Due to self-weight (about 10m) Through the jack down (about 38-40m) for loading jacks we use anchorage wire HYSD

bars Fe 500

Tilts and shifts

The inclination of the well from the vertical is known as tilt and the horizontal displacement

of the center of the well at the founding level from its theoretical position is known as shift

Tilt occurs due to uneven loading Sand blow is major reason for shifting of well. Sand blows beneath the well due to increase

in load on one side

The tilt of any well shall not exceed 1 (horizontal) in 80 (vertical), and the shift at the well base shall not be more than 150 mm in any resultant direction

Methods adopted for preventing shifting and tilting of well

1. Eccentric dredging

2. Eccentric loading

3. Pull to well

4. Push to well


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Figure 11: Some Ongoing Activities at Eastern Approach

4.4 Casting Yard

4.4.1 Batching and mixing of concrete

Ingredients

1. Cement: two type of cements are used OPC and Slag cement.

2. Water: treated water from R.O plant is used to avoid degradation in quality of reinforcement by

corrosion by fluorides and various salts present in bore-well water.

3. Aggregates: Coarse aggregates - 10 mm & 20 mm

Fine aggregates

4. Admixtures

Yard consists of two silos for fly ash and silica fume.

4.4.2 Pre Cast Technology

In precast technology the segments are pre-casted in casting yard far from actual site. After casting

they are transported to the site for erection. Main advantages of pre-casting are:1. It saves time

2. Prevents hindrance in normal life of people living near project site.

3. It is safer.

Signature bridge pre-casted materials are:


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a) Segments

b) Ribs

c) Kerb stone

d) Facia panel of crash barrier

4.4.3 Self-compacting concrete

Self-consolidating concrete or self-compacting concrete is characterized by a low yield, high

deformability, and moderate viscosity necessary to ensure uniform suspension of solid particles

during transportation, placement (without external compaction), and thereafter until the concrete

sets.

Such concrete can be used for casting heavily reinforced sections, places where there can be no

access to vibrators for compaction and in complex shapes of formwork which may otherwise be

impossible to cast, giving a far superior surface than conventional concrete. In our case SCC isused for casting of piers.

4.4.4 QC (quality control) lab

The various tests are performed here for concrete ingredients.

Tests performed for cement:

1. Fineness test

2. Sieve test

3. Settling test

Tests performed for aggregates:

1. Sieve analysis

2. Crushing value test

3. Impact value test

4. 10 % fines value test

5. Silt content

6. Specific gravity

7. Flakiness & elongation test

Test for concrete (non-self compacting concrete):

1. Slump test

2. Settling time test initial settling time, final settling time

3. Crushing value test (performed on cubes)


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5. Present Status

5.1 Eastern Approach

Flyover at Khajuri Chowk completed and opened to traffic on 01 March 2014

Bituminous road work completed and cement concrete road work in progress.

Embankment and cross drainage works for connecting flyover with Signature Bridge in

progress

5.2 Western Approach

Main flyover along Outer Ring Road completed and opened to traffic in Aug 2012 Construction work of 8 nos. loops in progress

5.3 Main Bridge (Cable Stayed)

The work of all foundations is in progress

Out of total 18 nos. well foundations, 16 nos. have been completed up to foundation level

The foundation works of all the open foundations (9 nos.) have been completed

Out of total 27 nos. piers, 24 nos. have been completed

The work at P23, the critical back stay foundation, is in progress

5.4 Expenditure report as on 15 th December 2013

Total Sanctioned Amount Rs 1131 crore.

Upto date Deposit received from PWD Rs 929.83 crore.

Upto date Expenditure as on 31-03-2014 Rs 709.70 crore.

(Approaches Rs 332.59 crore

Main Bridge Rs 289.88 crore

Other Rs 87.27 crore)


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6. Specialized Works for Main Bridge

Light illumination of pylon, bridge and flyovers will be done. 4 Inclined lifts will be there within

the pylon. Pylon access system will be built for full height of 151 m inclined pylon and full

lengths of 38 front and back cables for repair and maintenance and cleaning purposes.

Bridge structural health monitoring system will be developed. Sensors will be placed to measure

environmental load and structural response factors on bridge.

7. Conclusion

Summer internship opened our view about civil engineering. Till now we were doing mainly

theoretical studies but during our internship period we were exposed to various dimensions of civil

engineering. We got to know practically about various aspects of bridge construction. Besides civil

engineering we got opportunity to learn about management of such a big project. Handling such a

project requires a great dedicated team effort. This training provided us the practical knowledge

which cannot be explained in the institute campus nor in any laboratory.

8. References

1. Richi Verma (Jan. 16, 2014),Sun to light signature bridge. The Times of India

2. Presentation to MD DTTDC 07.04.14

3. May 28, 2014, Signature Bridge delayed, LG slams tourism industry. The Times of India

4. R. Kathik, Well Foundation. Youtube < https://www.youtube.com/watch?v=Mhxl7EH-b9I >

5. Foundation (engineering), Wikipedia, the free encyclopedia,
https://www.youtube.com/watch?v=Mhxl7EH-b9Ihttps://www.youtube.com/watch?v=Mhxl7EH-b9I


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Documents

Internship Report Bharat PDF