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INDEX

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CONTENT PAGE No. 1 INTRODUCTION 4 2 PROJECT DETAILS 5-8 3 BATCHING & MIXING PLANT 9-13 4 LABORATORY TESTS 14-15 5 CONSTRUCTION METHODS 16-17 6 CASTING OF SEGMENTS 18-22 7 TRANSPORTRATION & PLACING OF SEGMENTS 23-25 8 PILLING 33-36

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INTRODUCTION Precast segmental bridge construction involves a lot of process that includes casting of segments and parapet walls in the casting yard and then transporting them to the site where it is placed in between columns (cast in situ) with the help of various support system (here GSS used). In casting yard cage is formed properly with the help of drawing and bar bending schedule, which is placed over the bed, prepared according to the alignment of the segments either curved or fixed. Now internal and external shuttering is done along with bulk head (not required in case of match cast). Concrete mix which is properly designed as per required strength at batching and mixing plant is transported by transit mixer to the casting yard where it is poured using concrete pump and with the help of poker and formwork vibrator concreting work is completed. Now the completed segments are properly cured, marked and then placed in stack using gantry girder. Before transporting segments to the site, sand blasting is done over the cross section in order to increase friction. At site segments are launched using Ground Support System (GSS), temporary prestressed, properly aligned using lifting jack and after the entire span is aligned, cable wires are inserted and then it is prestressed using jack. Piling is done at the desired location using pile driver, auger is used initially for hard road, and then with the help of soil bucket and bentonite solution, then cage is put into the hole and concreting is done using tremie.

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HISTORY Kolkata Metro – the 1st Metro System in India The initiative had to wait for 2 decades when in 1969 the Metropolitan Transport Project was initiated. The master plan prepared by them in 1971 envisaged a network of 97.50 km consisting of three North-South corridors of which three were selected for detailed planning. These three lines were Dumdum – Tollygunge, Bidhannager – Ramrajatala and Dakshineswar – Thakurpukur. Based on traffic studies, the Dumdum – Tollygunge corridor was first selected for implementation and work started on 29th December, 1972. On 24th October 1984,the first stretch, a length of about 3.4 km between Esplanade and Bhowanipur was completed, the first metro line in India. Over the years, others stretches on the corridor were gradually completed and some extensions were also made. This corridor was extended to New Garia as late as 2010. The people of Kolkata, enjoyed benefits of a modern metro system. In today carries about 5 lakh passengers a day.

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ABOUT CURRENT PROJECT East- West Metro Corridor Project, Kolkata The master plan had already identified the corridor way back in 1971. The experience of India’s first metro and the success of the Delhi metro network contributed to the sanction of the East – West corridor connection Howrah Railway Station and Bidhannagar through an order dated 30th July 2008. Thus began the fascinating journey of building the East–West corridor, the line which would connect Howrah and Sealdah Railway Stations, two of the busiest railway stations in the world and which would pass through under Hooghly river, the first such river crossing in the country. A journey whose end is in sight, a journey which will give Kolkata its second metro; a metro the residents would be proud of.

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Kolkata Metro Master Plan

Kolkata Metro Railway Map (Metro Railway, Kolkata & East West Metro) In 2010, the Railway Ministry announced plans for the construction of five new metro lines and an extension of the existing North-South corridor. These new projects are:

Salt Lake City - Howrah Maidan (East-West Metro Corridor) Joka - BBD Bagh Noapara - Barasat via Biman Bandar (Airport) Baranagar - Barrackpore Noapara - Dakshineswar

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New Garia - Biman Bandar (Airport) Extension of Line 1 from Dum Dum to Dakshineshwar via Noapara

Line 6 (Kavi Subhash-Biman Bandar Metro) A connection between New Garia and the Airport (29.1 km) via E M Bypass, Saltlake and Rajarhat has started; it will help to reduce travel time between the southern fringes of Kolkata to Netaji Subhas Chandra Bose International Airport. The work on this New Garia-Airport line was inaugurated by Mamata Banerjee on 7 February 2011 with a project deadline of six years.[15] The link between Kavi Subhas (New Garia) and the airport, to be set up at a cost of Rs4 billion, will have 24 stations with the terminal Airport station being an underground one. The stations, as declared of now, will be named after eminent personalities.[15]

1. Kavi Subhash Metro Station (Intersection with Line 1) 0.00 km 2. Satyajit Ray Film and Television Institute 1.6 km 3. Mukundapur 3.0 km 4. Kalikapur 4.1 km 5. Ruby Hospital 5.1 km 6. VIP Bazar 6.40 km 7. Bantala 7.30 km 8. Science City 8.6 km 9. Beliaghata 9.5 km 10. Chingrighata 11.2 km 11. Nicco Park 12.6 km 12. Salt Lake Sector V (Intersection with Line 2) 13.9 km 13. Technopolis 15.1 km 14. Bidhan Nagar 16.2 km 15. Sub CBD-1 17.5 km 16. CBD-1 18.6 km 17. CBD-2 20.0 km 18. New Town 20.9 km 19. Convention Center 22.1 km 20. Sub CBD-2 23.30 km 21. City Centre 24.2 km 22. Rabindra Tirtha 25.1 km 23. VIP Road 26.7 km 24. Airport (Intersection with Line 4) 29.1 km

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Batching plant or a concrete batching plant A concrete plant, also known as a batch plant or batching plant or a concrete batching plant, is a device that combines various ingredients to form concrete. Some of these inputs include sand, water, aggregate (rocks, gravel, etc.), fly ash, potash, and cement. There are two types of concrete plants: Dry mix plants and Wet mix plants.

A Wet mix Concrete Batching plant combines some or all of the above ingredients (including water) at a central location in a Concrete Mixer. The mixer can be Single/Double Shaft type, Pan type or a Planetary type. The final product is then transported to the desired location. Dry mix differ from Wet mix plants in that Wet Mix contain a central mixer, which can offer a more consistent mixture in a shorter time (generally 5 minutes or less). A Mobile batch plant can be constructed on a large job site.

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Concrete mixing plant works Concrete mixing plant is divided into four parts: gravel feed, powder (cement, fly ash, bulking agents, etc.) to feed, water and feed additives, transmission and storage stirred their workflow shown in Figure 1. , the mixer control system power, into the human - machine dialogue operation interface, system initialization process, including recipe number, grade concrete slump, producers, etc. according to the amount of weight carried on each silo, weighing hoppers. detection, output material or material empty full signal, prompting the operator to determine whether to activate the control program starts stirring sand, stone belt motor fed into the metering hopper; open fly ash, cement tank valve, start the electromechanical screw conveyor ash cement to the metering hopper; open water reservoir and control valves admixture pool water and additives into the metering hopper metered meet the set requirements doo door open metering, mixing the ingredients into the mixer within already started to set. Time to open the mixer door, into the concrete mixer had received material.

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Chemical Admixtures Chemical admixtures are the ingredients in concrete other than Portland cement, water, and aggregate that are added to the mix immediately before or during mixing. Producers use admixtures primarily to reduce the cost of concrete construction; to modify the properties of hardened concrete; to ensure the quality of concrete during mixing, transporting, placing, and curing; and to overcome certain emergencies during concrete operations.

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In this project BASF MasterPolyheed 8650 is used as admixture.

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ABOUT USED ADMIXTURE MasterPolyheed 8650 - High range water reducing/superplasticising, admixture for precast and High performance concrete Formerly Rheoplus 71(UT) Working of MasterPolyheed 8650: MasterPolyheed 8650 is an admixture of a new generation based on second-generation polycarboxylic ether polymer with high early strength gains. MasterPolyheed 8650 is free of chloride & low alkali. It is compatible with all types of cements. Recommended uses:

MasterPolyheed 8650 is suitable for making precast concrete elements at all workability’s including Rheoplastic or Super workable concrete having fluid consistence, no segregation, a low water binder ratio and, consequently high early and long term strengths MasterPolyheed 8650 may be used in combination with MasterMatrix 2 (formerly known as GLENIUM STREAM 2) for producing Rheodynamic concrete, capable of selfcompaction, even in the presence of dense reinforcement with out the aid of vibration, for making precast elements. As an component of Zero Energy System™ Concreting in cold weather

Advantages of using MasterPolyheed 8650: MasterPolyheed 8650 helps to produce longer workability retention with improved rheology of concrete. Its improve properties of concrete when manufacturing sand is used instead of natural sand. It is mainly for Ready Mix concrete for < M-50 grade. The features and benefits of MasterPolyheed 8650:

Achieve high early strengths Produces Rheoplastic and Rheodynamic concretes having a low water cement ratio Optimise curing cycles by reducing curing time or curing temperatures Eliminate heat curing Eliminate the energy required for placing,compacting & curing (Zero Energy System™) Increase productivity/ reduction in cycle time Improve surface appearance Produce durable precast concrete elements Improved engineering properties, compared to traditional superplasticiser such as early and ultimate compressive and flexural strengths, reduced shrinkage and low permeability.

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TESTS CARRIED OUT IN LABORATORY Compressive strength of concrete: Out of many test applied to the concrete, this is the utmost important which gives an idea about all the characteristics of concrete. By this single test one judge that whether Concreting has been done properly or not. Compressive strength of concrete depends on many factors such as water-cement ratio, cement strength, quality of concrete material, and quality control during production of concrete etc. Test for compressive strength is carried out on cube. Various standard codes recommends concrete cylinder or concrete cube as the standard specimen for the test. American Society for Testing Materials ASTM C39/C39M provides Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens, For most of the works cubical moulds of size 15 cm x 15cm x 15 cm are commonly used.

This concrete is poured in the mould and tempered properly so as not to have any voids. After 24 hours these moulds are removed and test specimens are put in water for curing. The top surface of these specimen should be made even and smooth. This is done by putting cement paste and spreading smoothly on whole area of specimen.

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These specimens are tested by compression testing machine after 7 days curing or 28 days curing. Load should be applied gradually at the rate of 140 kg/cm2 per minute till the Specimens fails. Load at the failure divided by area of specimen gives the compressive strength of concrete.

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Construction Methods for Bridge 1. Cast-in-Situ Method This Method Prefer for Short Bridges. Time consuming is large in cast-in-situ construction as it involves following steps.

Segmental Construction Method Span-by-span

Erection on ground supported staging Casting of concrete Dismantling of staging

2. Precast Segmental Method This method is used for the long bridges. It is economical when there is large no of span. This method involves the following steps.

Casting of Precast segments in casting yard. Transporting the precast segments at the site. Erection of the precast segment using launcher or crane. External Prestressing. Grouting.

Segmental Bridge Construction A Segmental Bridge is a bridge built in short sections (called segments), that is one piece at a time. And then segments are erected to make the bridge. The bridge is either cast-in-place or precast. Advantage of segmental bridge construction

Very economical for long spans. Prefabricated segments provides more quality control. The structure can be fully loaded immediately after being prestressed. The pre-stressed cables can be inspected and replaced at all times. Low weight due to thin bridge sections.

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Industrialization of the construction process. Innovations in construction equipment. Low maintenance costs. Speed of construction, time taken less

Disadvantage of Segmental bridge construction Segmental Construction Method Progressive placement

High construction loading or high technology is used. Need high safety precautions during construction Extra cost (due to more prestressing required)

History of Segmental bridge construction Segmental bridge construction first appeared in the early 1950s. The first cast-in-place segmental concrete bridge, built in 1950, across the Lahn River in Germany. The first precast segmental concrete bridge, built in 1962, across the Seine River in France. Classification of segmental bridges – Segmental bridges is classified under the following Categories.

Balance Cantilever Bridges Progressive Placement Bridges Span-by-Span Constructed Bridges Incrementally Launched Bridges

Construction of Segmental Bridges The following steps are used for the construction of Segmental bridges. Casting of Segments– Two method used for casting of segments Short Line Method- In this rate of segment production is slow. Three or four segments cast at a time. Long Line Method- In this rate of segment production is fast. Segments equal to one span cast at a time. After casting the segments are stored at staking yard and curing of segments will be done.

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SEGMENT Segments are slices of a structural element between joints which are perpendicular to the longitudinal axis of the structure stressed together by means of prestressing tendons.

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Casting of Segments– Two method used for casting of segments Short Line Method- In this rate of segment production is slow. Three or four segments cast at a time. Long Line Method- In this rate of segment production is fast. Segments equal to one span cast at a time. After casting the segments are stored at staking yard and curing of segments will be done.

DESIGN OF SEGMENT The design drawing of segment (Standard drawing showing for package: ANV-1/ANV-2) has been prepared on the basis of DD Drawing, dimensional details of superstructure for 22,25,28,31 m span revision-A which is approved by RVNL/IIT-D on 05/10/2012 and designed by STUP CONSULTANTS PVT. LTD.

Reinforcement cages

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The production of reinforcement cages is a cumbersome task that requires a lot of manpower or costly equipment, which is sometimes irrelevant for a particular project. The set elements that form the reinforcing cages are realized in another factory and delivered to the site in form of pins, frames and prefabricated curved wire mesh. The distribution device for the supply of reinforcement is usually placed next to the segment fabrication lines. The reinforcement carrousel is only used for the assembling process. All the parts are put into the jigs duringthe different working stations. At the end of cycle, the reinforcing cages are complete and ready to be used. The supply of the mould is made by means of motorized hoists placed above the storage which moves to the reinforcement station and installs the reinforcing cage.

Transfer of cages to the concreting area Monorail: The constant supply of reinforcement cages for the moulds from the reinforcement carrousel to the reinforcement workstation of the segment carrousel is made by a monorail with movable hoist, runway, electricity and automatism. The reinforcement cages are placed in respective moulds and backed with bulk head.

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Then, concreting is done.

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After concreting is completed, the segment is placed for curing. And after 24hr the moulds and bulk head is removed. The segment is then cleaned by sand blasting method for getting a better surface. Then the ready segment is numbered accordingly and transferred by Gantry crane to the place from where it can easily be transferred to the site of placing.

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TRANSPORTATION & PLACING OF SEGMENTS: Transfer the segment at erection site: After casting or curing of segments are transferred at erection site with the help of traveller or crane.

Erection of the segments The precast segments are erected on the sites by following erection methods.

Balanced Cantilever erection Progressive Placement erection Span by Span erection Incremental Launching erection

Here, in this project, the erection method which is used is standard scaffolding (span by span erection).

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High Machineries are used for the erection of segments some of the following.

Launching Truss & accessories Launching girder & accessories Gantry crane or other cranes Hydraulic jacks Travelers

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SETTING OF POSITION OF SEGMENT The position of segment is fixed so that it must be in level as required by the help of hydraulic machine on which the segments are placed. Epoxy Gluing- In between the two segments epoxy Gluing is used to prevent the leakage of grout during grouting.

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PRESTRESSING After the placing of segments, temporary prestressing is done, it is necessary in order to maintain the correct alignment and also to balance its own self weight. As the temporary prestressing is applied then final prestressing procedure starts. At first, the cable is inserted in the duct as mentioned in the design, then bearing plate is introduced for insertion of cable.

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Then the master wedges are used for avoiding slipping of the cable.

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Then, hydraulic jack is onto cables after master wedges, it is used for prestressing.

The given (as per design) prestressing pressure is applied on the cable by the hydraulic jack.

Elongation length is measured corresponding to the applied pressure. If it is okay then the prestressed cable is left for 24hrs. undisturbed to avoid slipping failure. After this, grouting is done.

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Then, the extra extended portion of cable is cut and cementing cover is applied.

A bearing cover is also applied for the setting of cement and after certain period it is removed.

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After certain period (24hrs.), the cover is removed.

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PILING The location where piling is done is recognised by survey details and design drawing manual. Once the location is fixed, some excavator is used for excavation of bore hole. The upper surface of the location where boring is to be done was bituminous road (where we were in). So, auger is used for this hard bituminous road surface up to certain depth.

As the afterward soil is silty in nature so we do not need auger for excavation, then we use soil bucket up to the desired depth as per design.

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Bentonite is used to maintain soil stability before the whole excavation and casing is put in the soil and it advances downward as excavation is done. Then, concreting is done by use of tremie.

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Here we used pile driver for excavation.