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JAIPUR METRO RAIL CORPORATION LTD (Phase-I) Mansarovar to Badi Chaupar
Presented By,Rajendra Prasad Meena(12113084)B.Tech 4th year (CE)IIT Roorkee.
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ACKNOWLEDGEMENT
The work on this project was conducted as a part of my summer training during 18th May 2015 to 1st July 2015.Appreciation is expressed to the members who served as the Technical Advisors for their input and assistance. The support provided by Executive Director Mr. Vijay Kumar Gupta and Manager Mr.Ravi Mathur is also acknowledged. Appreciation is also acknowledged to Jaipur Metro Rail Corporation Ltd. for allocating their resources and technical support.
Rajendra Prasad Meena
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NOTES
1. THE REINFORCEMENT SHALL BE OF THERMO MECHANICALLY TREATED
BARS (TMT) GRADE Fe-500
2. MINIMUM VERTICAL CLEARANCE IN RAILWAY SPAN = 5.5 m
3. THE DIMENSIONS AND LEVELS SHOWN IN THE DRAWINGS ARE
TENTATIVE
4. MAXIUM SPEED =95kmph
5. GRADE OF CONCRETE FOR VARIOUS STRUCTURES SHALL BE AS FOLLOWS :
ii) Pile cap and open foundation - M-35
iii) Piers - M-40
iv) All precast element for viaduct and station - M-45
v)Cantilever piers and portals - M-45
vi) Other miscellaneous structur - M-30
i) Piles - M-35
CONTENTS
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S.No Topic Page
OVERVIEW 5
1. INTRODUCTION
2. CIVIL ENGINEERING
3 RELOCATION / RESETTELEMENT
3. DESIGN OF PRESTRESSED CONCRETE-I GIRDER BRIDGE
4. PRESTRESSED CONCRETE
5. PRE - TENSIONING
6. POST - TENSIONING
8. PIER & ABUTMENT CONSTRUCTION
9. BRIDGE BEARING
LIST OF REFERENCES
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OVERVIEW
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INTRODUCTION
The project is planned along two corridors. The East-West Corridor and the North-South Corridor. The East-West Corridor from Mansarovar to Badi Chaupar, with a total length of 12.067 Kms. is being executed as phase-I of the project. The North-South Corridor from Ambabari to Sitapura with a total length of 23.099 Kms. Shall be taken up as phase-II of the project.
Performance Parameters
The recommended performance parameters are:
Maximum Operating Speed : 85 kmph
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Acceleration : 0.82 m/s2 +_ 5%
Deceleration : 1.1 m/s2 (normal brake)
: 1.3 m/s2 (Emergency brake)
Civil EngineeringGEOMETRIC DESIGN NORMS:
The design parameters related to the Metro system described
herewith have been worked out based on a detailed evaluation,
experience and internationally accepted practices. Various
alternatives were considered for most of these parameters but the
best-suited ones have been adopted for the system as a whole.
Elevated Sections:The viaducts carrying the tracks will have a vertical clearance of
minimum 5.5 m above road level. For meeting this requirement with the
‘Box’ shaped pre-stressed concrete girders, the rail level will be about
9.8 m above the road level. However, at stations which are located
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above central median, the rail level will be 12.5 m above the road level
with concourse at mezzanine. These levels will, however, vary
marginally depending upon where the stations are located.
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Underground sections:Rail level at midsection in tunneling portion shall be kept at least 12.0 m below the ground level so that a cover of 6m is available over the tunnels. At stations, the desirable depth of rail below ground level is 12.5m; Track centre in underground section to be constructed byTunnel Boring Machine (TBM) is 13.05m to accommodate a 10m wide island platform. Track centre in underground section to be constructed by cut and cover method is 4.5m.
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Gradients:Normally the stations shall be on level stretch. In limiting cases station
may be on a grade of 0.1 %. Between stations, generally the grades
may not be steeper than 3.0 %. However, where existing road gradients
are steeper than 2 %, gradients or for Switch Over Ramps upto 4%
(compensated) can be provided in short stretches on the main line.
Viaduct Structure:The proposed viaduct structure for the Jaipur Metro is Pre-cast
segmental box girder, carrying two tracks supported on single pier
located on the median of the road. Road clearance of 5.5 m is ensured
below the viaduct structure. The foundation shall be pile foundation at
most of the locations. Open foundations are possible at certain isolated
locations. The superstructure shall be pre-cast segmental construction
which will cause minimal inconvenience to the road users during the
execution stage.
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RELOCATION / RESETTELEMENT
The project involves relocation of few shops, commercial cum residential
buildings and hutments along the alignment. Compensation for
relocation of these affected structures shall be paid and it has been
considered in the project cost estimate. The alignment has been so
chosen, that it remains mostly within the government land. However, at
certain locations while negotiating the curves, the land acquisition
became inevitable. It is proposed to invite bids from private developers
to offer constructed tenements against TDR and cash components in
their own land.
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. DESIGN OF PRESTRESSED CONCRETE-I GIRDER BRIDGE
In conventional structural design process, the design method proposes a certain solution that is corroborated by mathematical analysis in order to verify that the problem requirements or specifications are satisfied. If such requirements are not satisfied, then a new solution is proposed by the designer based on his intuition or some heuristics derived from his experience. The process undergoes many manual iterations before the design can be finalized making it a slow and very costly process. There is no formal attempt to reach the best design in the strict mathematical sense of minimizing cost, weight or volume. The process of design is relied solely on the designer's experience, intuition and ingenuity resulting in high cost in terms of times and human efforts.
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 in practical with ordinary reinforced concrete. Pre-stressing tendons (generally of high tensile steel cable or roads) 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. Traditional reinforced concrete is based on the use of steel reinforced bars inside poured concrete.
Girders arrangement in a bridge
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PRESTRESSED CONCRETEPre-stressed concrete is a method of overcoming concrete's natural weakness in tension. 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. Traditional reinforced concrete is based on the use of steel reinforcement bars, rebars, inside poured concrete.
Forms of Prestressing Steel Wires Prestressing wire is a single unit made of steel. Strands Two, three or seven wires are wound to form a prestressing strand.
Tendon A group of strands or wires are wound to form a prestressing tendon.
Cable A group of tendons form a prestresseing cable. Bars A tendon can be made up of a single steel bar. The diameter of a bar is much larger than that of a wire. Nature of Concrete-Steel Interface Bonded tendon When there is adequate bond between the prestressing tendon and concrete, it is called a bonded tendon. Pre-tensioned and grouted post-tensioned tendons are bonded tendons.
Unbonded tendon When there is no bond between the prestressing tendon and concrete, it is called unbonded tendon. When grout is not applied after post-tensioning, the tendon is called an unbonded tendon. Stages of Loading The analysis of prestressed members can be different for the different stages of loading. The staged of loading are as follows :
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1) Initial : It can be divided into two stages. a) During tensioning of steel. b) At transfer of prestress to concrete. 2) Intermediate : This includes the loads during transportation of the prestressed members. 3) Final : It can be subdivided into two stages. a) At service, during operation b) At ultimate, during extreme events. Advantages of Prestressing :
The prestressing of concrete has several advantages as compared to traditional reinforced concrete (RC) without prestressing. A fully prestressed concrete member is usually subjected to compression during service life. This rectifies several deficiencies of concrete. The following text broadly mentions the advantages of a prestressed concrete member with an equivalent RC member. For each effect, benefits are listed. 1) Section remains uncracked under service loads
Reduction of steel corrosion. (Increase in durability) Full section is utilised. Hence higher moment of inertia (higher stiffness)
and less deformations (improved servicability). Increase in shear capacity. Suitable for use in pressure vessels, liquid retaining structures.
2) High span-to-depth ratios Reduction in self-weight. More aesthetic appeal due to slender sections. More economical sections.
3) Suitable for precast construction Rapid construction Reduced maintenance Better quality control Availability of standard shapes Reduction of formwork
Limitations of prestressing:18
Although prestressing has advantages, some aspects need to be carefully addressed.
Prestressing needs skilled technology. Hence, it is not as common as reinforced concrete.
The use of high strength materials is costly. Additional cost in auxiliary equipments is there. There is need for quality control and inspection.
Types of prestressing:
Prestressing of concrete can be classified in several ways. The following 2 major classification are discussed below.
Pre-tensioningThe tension is applied to the tendons before casting of the concrete. The pre-compression is transmitted from steel to concrete through bond over the transmission length near the ends. The following figure shows manufactures pre-tensioned electric poles.
Pre-tensioned electric poles
Post-tensioning
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The tension is applied to the tendons (located in a duct) after hardening of the concrete. The pre-compression is transmitted from steel to concrete by the anchorage device (at the end blocks). The following figure shows a post-tensioned box girder of a bridge.
Post- tensioning of a box girder
LIST OF REFERENCES
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1. IRS - Steel Bridge Code: Code of Practice for design of Railway Steel Bridges.
2. IRS - BI :79; Code for design of steel bridges, Research Design and Standards Organization, Indian Railways, Lucknow, India.
3. Bridge Rules, Ministry of Railway (Railway Board)
4. IRC :83 (Part I) : Standard specification& code of practice for road bridges, part I- 1982 Metallic Bearings, Indian Roads Congress, New Delhi, India.
5. Concrete Bridge Practice - Analysis, design and economics - By V.K. Raina.
6. AASHO: Standard specification for highway bridges, The American Association of State Highway Officials, Washington, USA.
7. Internet site :
8. Wikipedia
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