Railways & Metros

Steel Roofing for Bamandongri & Kharkopar Railway Stations

Bamandongri and Kharkopar Railway Station was envisioned as large-scaled architectural landmarks in the ever-expanding fabric of the urban sprawl at Ulwe and beyond. With the upcoming Navi Mumbai International Airport (N.M.I.A) at Uwe, the anticipated development of housing, commercial activity, industries, and various other domains, is projected to be one of the largest in 21st century India. The complexes have been designed to provide seamless transfers between connecting nodes and further destinations.

Design Ideology
Theme-based station development ideas was presented for the four stations – Sagarsangam, Targhar, Bamandongri, and Kharkopar respectively. The planning of Bamandongri & Kharkopar railway station has been ideated to accommodate future capacities with a strong emphasis on regional interconnectivity.

A contemporary theme of the geometries of motion has been the inspiration for the architectural expression of the projects. Grand concourses on both sides of the station welcome and guide the users to the ticketing areas and subways that lead to the elevated platform areas. On entering the platform level, the platform roof design based on efficient structural sizing for a 38M span provides natural light and is made up of aluminum standing seam interwoven with polycarbonate. This presents a grand experience to the commuters at this transit hub.

Kharkopar Railway Station has also been designed to be one of the finest transit architecture expressions of Modern India. The location being immediately across the International Airport, the interface of the Sky Train, Metro, Railway Harbor line and public buses have been meticulously planned for the efficient functioning of the multi-modal transit hub. They shall complement the state-of-the-art development of Navi Mumbai International Airport and the allied growth and infrastructure development of various sectors. The stations along the N.U.R corridor will provide a great sense of pride for residents and be a prized possession of CIDCO, Indian Railways and mostly, for the residents of the emerging city.

Structural Specifications
Following are the structural elements we used for Bamandongri and Kharkopar Railway Stations:

  • Main frame profile for column – Dia 1200 x25th, top circular member – CHS 356X12thk
  • Secondary frame – CHS 356X12thk, SHS 300, fabricated box from ISMC300

Uniqueness
The Unique things about the structure are as follows

  • Parabolic pipe arrangements for roof.
  • Color combination of roof sheet and extended arrangement for polycarbonate sheet.
  • Fins on both side of elevation

Considering complex geometry, InSteel was entrusted with single point responsibility of Structural design, fabrication , erection, painting and roofing work. The main roof is barrel vault having 32 mtr span at a height of 10 mtrs from ground level. The 1200 dia massive steel column was designed to accommodate three rafters each 354mm dia pipe in a parabolic vault form. The enitre fabrication was carried out using high precision CNC cutting and welding machines, enabling perfect fitment of profiled cut circular hollow sections with each other. The bending of huge arches was a hurculine task but was managed well with experienced team of inhouse engineers and fabricators. The erection of the entire structure was completed in 5 months time using high capacity mobile cranes. The roof geometry formed has two distinctive shapes, side cones being utilised to fix Polycarbonate sheets allowing ample light inside and central petal shapes covered with opaue standing seam aluminum roofing giving entire roof a substance and solidarity.

Raju Jagtap
Managing Director, INSTEEL Engineers Pvt Ltd

Steel Used
The Steel Sections with grades used for the project are:

  • Material grade – IS2062 – E250
  • Sections – ISMC-75, ISMC-100, ISMC-300, ISMC-400, CHS355.6X12, CHS406X12, PIPE 900X12, PIPE 1200X25, RHS 240X120X6, RHS100X100X5
  • PLATE THICKNESS – 6 – 50MM

For Bamandongri station 2500MT of steel and for Kharkopar station approx. 1500MT of steel was used

Connection design was used for member to member, for easy erection process. Whereas Crain 25MT, 50MT and 100MT was used along with H frame scaffolding, fabricated Derick as well as Mechanical and electrical winch was used.

Encounters
The major challenges we faced during fabrication and erection of structural steel:

  • 36MTR circular truss erection at more than 15mtr height.
  • Erection of parabolic truss at zero – zero level.
  • To overcome this issues, hi-tech equipment and skilled manpower were used.

The team followed their own specialized HSE program. The safety engineers’ team was having very good experience for fabrication and erection of such structures. Everyday mockup and safety drills for each workman with proper monitoring systems was followed.

Welding processes used for this project are:

  • SMAW – Shielded metal arc welding
  • MIG –metal inert gas welding (co2)
  • SAW – Submerged arc welding

For Bamandongri station total manpower was around 52 (Average) and Manhours were 104832 approx.

And for Kharkopar station total manpower was around 45 (Average) and Manhours were 75600 approx.

Features
The designs are based on efficient structural design, low maintenance structures, naturally lit and ventilated public areas, efficient circulation, and a grand experience to the commuters at the transit hub. Building material: Along with the desired design performances, Life Cycle Analysis methodology has been used for selecting building materials. The primary structure is designed in M40 grade of RCC and the multi cell polycarbonate sheets are used for sky lights on roofing. These lightweight low maintenance and durable sheets enabled the designers to reduce the dead load on the structure and bring in adequate diffused daylight on the platforms.

Building materials like material for flooring, cladding, etc. all have been chosen based on their high rating on the life cycle analysis performance. Services: The total connected load of the project is 440 kW. Provision for solar lighting system of is provided on Aluminum standing seam roof based on clip-on system. 75,000 liters of water per season is collected via rainwater harvesting system installed at site and is used for flushing and cleaning.

This project has been a unique combination of the highly technical aspects to be combined with multi modal transit hub planning along with peak hour crowd management while designing an iconic structure that shall become identity of the said locality.

Fact File

Client: CIDCO
Architect: Hiten Sethi and Associates
Structural Consultant: INSTEEL Engineers Pvt Ltd
Fabricator: INSTEEL Engineers Pvt Ltd
Steel Supplier: Jindal Steel, SAIL, Tata Steel & Apollo
Status: Completed

Redevelopment of Habibganj station

On its 67,368 kilometers of track, Indian Railways have 1,47,523 bridges as on 1st April 2018. These bridges make it possible for railways to move across mighty rivers, valleys, and other obstructions. Bridges are also required to permit road vehicles, metros, railways, pedestrians etc. to cross railway tracks.

The field of construction of bridges is very challenging. The water in rivers, great heights/depths near bridges, their remote locations etc. poses challenges to bridge engineers.

If bridge cannot be cast in place, then launching of bridge components is involved which poses its own unique challenges. However, if the bridge is to be constructed near/across running railway tracks, the problem is greatly compounded.

Habibganj is the first railway station in India which is taken up on Public-Private Partnership (PPP). It was awarded by Indian Railway Stations Development Corporation Limited to the Developer Bansal Pathways Habibganj Private Limited.

The redeveloped station aims to provide large waiting area above tracks, called concourse, where passengers shall wait for their trains comfortably. The movement of departing and arriving passengers is segregated, all components are well designed so that the station is 100 per cent divyang friendly and is a delight for all people visiting it.

The commercial spaces – retail, hotel, offices etc., are also well integrated with the station to provide better ambience to the entire station complex.

Salient Features

Concessioning Authority:
Indian Railway Stations Development Corporation Limited

Developer:
Bansal Pathways Habibganj Private Limited

Cost of Mandatory Development:
Rs 100 Cr

Real Estate Built Up Area:
12 lakh square feet, cost approx. Rs 350 Cr

Lease Period for Commercial Development:
45 years

Operation & Maintenance of Habibganj Railway Station:
8 years

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Consultants
Planning:

  • GMP Gmbh – a German architectural firm along with ICT Pvt Ltd
  • Detailed Design:
  • AECOM India Pvt Ltd
  • Proof Check:
  • Sterling Engineering Consultancy
  • MEPF Proof Check:
  • Pankaj Dharkar Associates
  • Green Building:
  • Blue Earth Enterprise

Steel Work
Total Scope of Structural Steel Work:

  • 2550 MT
  • Total Sheeting Area:
  • 30900 sqm
  • Structural Steel Fabricator:
  • HMM, Ambala
  • Sheeting & COP Erection:
  • Bansal Laboratories
  • & Equipment Pvt. Ltd.
  • Concourse Launching:
  • R-KAD

Use of Steel
Due to various advantages in works across/near railway tracks, steel has been used extensively in station redevelopment project. The Cover of platforms, the concourse and roof of concourse/ new station buildings are done in structural steel.

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Challenges

  • Constructing bridges near/across running tracks requires extra care for:
  • Working in constrained Spaces: The “Schedule of Dimensions (SOD)” of the railway tracks which defines the outer limits of the vehicles moving on the railway tracks is required to be respected at all times and must be checked at different stages of construction.
  • Securing the Tracks: The railway alignment is also called “permanent way” and ought to provide firm ground support to trains at all times. Whenever the ground is excavated for construction of foundation or for any other purpose, it is required that track stability be ensured.
  • Respecting the restrictions of Overhead electric lines: The Overhead electric Equipment (OHE) supplies 25,000 Volts power to power the trains and it is dangerous for any person within 1.5m of the equipment. Any bridge construction scheme always must keep this severe restriction in mind.
  • Securing the Trains: While working above the tracks, we must make sure that nothing falls onto the trains/ people moving underneath. Even while working by the side of tracks, it is necessary that nothing leans onto the tracks.
  • Working in constrained times: Any work across or near tracks which affects the SOD or track stability or comes within 1.5m of OHE requires shutdown of train operations. The shutdowns are only available for small durations, usually less than 3 hours, in one go. If multiple tracks are involved, then the shutdown time is even more constrained. Any scheme for bridge works, therefore, must plan the work in small units which can be completed within the shutdown time available such that the trains can be run safely immediately after the shutdown time is over. Working in such constrained times often leads to errors and affects safety as well as quality of work.

Planning of Concourse for Habibganj Station Redevelopment Project
Habibganj station is on a very busy Delhi – Chennai route and has 12 tracks (including two tracks for maintenance of coaches). The concourse is meant to be a waiting area for passengers in the redeveloped station and is 85 m long and 36 m wide, with a connecting Bridge of 56m long which is 15 m wide. To provide clearance for the trains to move and the Overhead Electrical equipment, the bottom of girders is 7.4 m above the tracks.

Column layout for the Concourse – station buildings are on both sides and the columns are on platforms.
Columns can be provided only at the platform locations and hence the total length of concourse is divided into 4 spans (36.51m, 36.56m, 31.26m and 30.15m). The steel plate girders were fabricated at HMM workshop in Ambala and transported over road trailers due to which the maximum length of individual piece was 12.5 m. The site connections of girder pieces were with Friction Grip bolts and the composite deck was cast-in-situ.

Design features

  • Type of girder: Welded steel plate girders, with composite RCC slab
  • Maximum length of girder: 47.16m (span 2) [36.56 +10.60 (cantilever)]
  • Depth of Steel girder: 1750 mm
  • Maximum length of individual piece: 12.5m
  • Maximum weight of individual Steel piece: 10.95T
  • Maximum weight of single girder in span length: 35.42T (Span-2, with Cantilever)
  • Maximum weight of assembled span: 382.612T (14 girders with bracings etc.)
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Launching Options of girders:

  • Various options studies for launching included launching using cranes, cantilever launching, use of launching girders etc. The site was very congested due to various features:
  • There were two subways on either side of the concourse. The subways had ramps coming out which made the space on the platforms restricted. Since the concourse location was the same as existing Foot Over Bridge, the subways had to be completed and commissioned before the concourse construction started.
  • Being on extremely busy train route meant that the traffic shutdowns were available for very less duration and even the planned shutdowns are not always possible due to complex traffic pattern.
  • Presence of OHE creates issues in getting clear operating volume for crane operations difficult. Further, due to cramped space on platforms, cranes could not be placed on platforms. The radius for handling the single girders of 35.42 T was very high for which cranes of required capacity were not available.
  • Cantilever launching was feasible but required a launching nose to be fabricated. But handling of cantilevers is always tricky. From safety considerations, the train movement is to be stopped when the cantilever launching is being done. This meant that both the main tracks were required to be closed simultaneously, which is very difficult. The scheme not only was difficult, but also costly and slower.

Finally, from techno-economic considerations, launching was planned to use a launching platform parallel to proposed Air Concourse. The design was proof checked from VNIT, Nagpur and then checked by the design office of West Central Railway. The statutory sanction from Commissioner of Railway Safety, Central Circle Mumbai was obtained before commencement of work.

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Use of BIM and Virtual
Construction Technology
Being a complex scheme, involving requiring transport of heavy girders over running tracks, it was imperative for all the stakeholders to clearly understand the complete process and chronological sequence of events.

Also, the team wanted to verify the complete design and resolve any constructability issues. Therefore, scaled Building Information Model was created for the complete launching structure along with micro simulations showcasing the progress of construction with time, generally known as 4D micro simulations.

4D sequences, 3D logistics and instructions diagrams were circulated to help all stakeholders better understand the process flow. This enabled all the agencies to clearly understand the process and sequence of construction. All agencies could prepare, take all precautions for smooth working and ensuring safety precautions. All fabrication drawings for temporary structure were also generated from this BIM Model itself, to eliminate errors during drafting.

Habibganj railway station redevelopment project is a unique project, taken up for the first time in India and lots of challenges were there which required fresh thinking. Experienced railway engineers were initially apprehensive about such a project coming up in a busy working station. The Developer, the designers, the execution agencies are to be saluted for coming up with good solutions and executing the work safely/smoothly without adversely affecting railway operations.

Baldev Singh
Chief General Manager (Projects),
Indian Railway Stations Development Corporation

Launching Scheme

  • A temporary launching platform was constructed across the yard (over all tracks) parallel to concourse with supports at platforms and temporary supports between tracks wherever space was there. The launching platform height was kept sufficiently high to provide electrical clearance from OHE as per standards. Due to less load, the temporary launching platform could be launched using small 10T capacity Hydra Cranes in traffic shutdowns of small duration.
  • Launching girder being assembled with both main lines closed – delayed the work by 20 days
  • The girder pieces were received in yard near east side station building and a lifting arrangement was provided to place these on the launching platform on dip lorries. For stability purposes, two girder pieces were assembled before placing on launching girder. The girder pair was pulled across tracks over launching platform using winches.
  • The sliding platform at the same height are provided, when girder pair arrived at position longitudinal movement is stopped and lateral movement start. After arriving to position the girder is lowered with the help from winch and jacks.
  • Bringing Girders to proper location and moving along tracks the launching platform
  • The Roof structure is prefabricated steel structure, which is being erected simultaneously. This work will commence after all girders are in place and RCC deck casting is complete.
  • Benefits of the scheme chosen:
  • Space planning: The Schedule of Dimensions and clearances of OHE were always respected. With all the work being done in air above the tracks, the platforms were left free for use by passengers.
  • Securing the Tracks: Proper RCC foundations were provided for the temporary launching platforms. The casting of two foundations, which were not on platforms, was done with suitable precautions and traffic shutdowns.
  • Securing the Trains: To ensure that nothing shall fall onto the passengers moving on platform, safety net was provided below the arrangement on platforms.
  • Respecting the restrictions of Overhead electric lines: Proper sheeting was provided in launching platform which took care of all concerns regarding the OHE lines. The platform was constructed sufficiently above the electrical equipment.
  • Working in constrained times: This beautiful scheme required only a few shutdowns initially for launching of the platform and rest of the launching work could be done over the platform. The time was not constrained for most part of erection.

Conclusion
Extensive use of steel in concourse, and the launching arrangement addressed the major concern of providing such a huge concourse over very busy Delhi – Chennai trunk route of Indian Railways. The versatility of steel as a material of construction has been well demonstrated in this project.

(Contributed by Vivek Bhushan Sood
Chief GM (Civil), Indian Railway Stations Development Corporation)

Building Bridges to the Future

Construction of road or rail bridges, like every new infrastructure is an exceedingly complex process. As the demand for transportation rises, connecting remote locations, complex bridge structures now span over massive water bodies or deep troughs and valleys in mountain regions. Hence, bridge construction projects, necessitate seamless and free-flowing communication among different stakeholders on a real-time basis. This is because even the slightest of error or delayed information can set a project back with costly delays or rework, thus adversely affecting project timeline and profitability.

A lot of these challenges can, however, be effectively mitigated once we move from paper-based workflows to integrated and connected data models. Trimble’s Tekla Structures offers an intelligent, parametric Bridge Information Modelling (BrIM) solution for the constructible design of all bridge types, sizes, and materials. It is a breakthrough product in digitalizing bridge construction with cutting-edge, amazingly accurate and highly detailed 3D models.

What is BrIM?
BrIM, or Bridge Information Modelling is an advanced modelling solution that is customized for bridge projects. It not only provides a comprehensive representation of the physical and functional characteristics of a bridge asset but also records information for its entire lifecycle, and this helps in improving the efficacy of the entire construction workflow, which in turn leads to reduced cost and early completion of the project. BrIM by Tekla Structures generates integrated and connected 3D models, which in turn enable the construction of highly complex bridge construction projects with greater efficiency and precision.

Every infrastructure developer around the world jostles for one overarching goal, which is to deliver the project on time and within budgets. This applies as much for tall skyscrapers as it does to complex bridges. A growing majority of them are now also striving for sustainable and environment-friendly construction. Use of cutting-edge BrIM software helps bridge project owners achieve both these goals.

BrIM Principles – Open approach, standardized data, Greater efficiency throughout the workflow

The main principle which governs BrIM is that the entire lifecycle of bridge construction, from design to engineering process to maintenance, is amalgamated into one software. It helps streamline construction processes from start to finish and maintenance and makes efficient collaboration possible between all project parties, including relevant authorities. Upon completion, BrIM serves as a digital documentation tool for smart facility management too.

One of the most significant advantages of BrIM is that it streamlines the design phase and avoids multiple inputs of the same data and duplication errors. In addition to this, BrIM supports data standardization, which enhances collaboration among different stakeholders and allows interoperability, which enables it to work seamlessly across a wide range of construction software and hardware. The same model can connect and interact with a variety of modern construction tools: from 3D printing and Augmented Reality (AR) tools to connected sensors and devices that make up the Internet of Things (IoT).

Does the software do everything you need – manages changes, LOD, future-ready?
The core idea of BrIM is that you can have the entire bridge in one software. This way, precast concrete or cast in place modelling, rebar, steelwork and steel connections, formwork and even construction planning schedules – all of it – can be done in one software, no matter what kind of bridge you’re building. This helps all project parties collaborate without delays, everyone always has access to up-to-date information, and clash-checking is a breeze.

In bridge design, changing one detail might affect various others as well. With the right kind of BrIM, the changes can be made and managed all on one software, without the need to keep on reprinting countless stacks of paper.

Having the drawings and schedules of quantities always updated and representing the model accurately is a must. On top of this, automatic updates ensure all changes are immediately delivered to all project parties, reducing risk of rework throughout the process. A great example is when the concrete geometry needs to change, the reinforcement adapts to the new shape.

Due to high Level of Development (LOD), BrIM boosts the constructability of bridge design with accurate information. As stated earlier, it also brings consistent documentation available to all parties regardless of which software they use. Accurate, data-rich models and simulations allow one to estimate the material needed, which greatly aids steel and rebar workshops and precast processes.

Fabrication information can be organized and managed according to project progress, and hence wastage can be avoided along with minimum delays in the project schedule. With BrIM, it is possible to compress project schedules due to a more efficient workflow, accurate information, and timely communication.

BrIM allows bridge owners to have easy access to data-rich, as-built models of their asset long after the construction has been completed. The stored data is routinely updated and can be easily and effectively utilized for smart asset management. In other words, BrIM can potentially lead to the construction of intelligent bridges in the future that would communicate their health status on an ongoing basis for optimal maintenance.

BrIM can capture the structure and alignment of the road, railway, or the terrain – depending on the kind of bridge you are building. All input, ranging from geo models to scanned images, can be utilized in ways that physical drawings cannot compete against. A common BrIM language enables authorities, governments, municipalities, and industries to procure and record data of bridge projects better during construction. With bridge information modelling, inspections, maintenance, and repair can be managed efficiently and purposefully, as all construction stages have already been reliably documented and are easily available on hand.

Seeing is believing
An excellent example of BrIM in action is its use in the construction of Chenab Bridge in Jammu & Kashmir, the tallest and longest-spanning railway bridge of its kind in the world. Use of intelligent parametric Tekla Structures has allowed the construction team to execute logistics and optimize schedules in harsh mountainous terrain. BrIM can capture the alignment of the road, railway, or the terrain – depending on the kind of bridge that is to be constructed. The bridge, erected on Himalayan bedrock with foundations approximately 40 metres high and 50 metres wide, the arch and piers of the bridge are masses of steel trusses. In contrast, the foundations and the approach viaduct piers are made of concrete.

The arch is erected with a cableway crane, after which the deck is then launched into place and joints assembled with a total of 600,000 bolts! This project is also a great example of Green construction, which saves materials, time, labor, money and ensures nearly zero waste using technology. BrIM was used for a complete simulation before the construction started, detailed 3D models allowed a high level of development (LOD) and accuracy of the model made it most suitable to be used for fabrication in the temporary workshops on site itself. The Chenab Bridge fully demonstrates the value that BrIM brings to modern bridge construction. The ever-rising costs and complexity of these structures demand solving of problems problem solving before they are manifest in real life. Bridge Information Modelling (BrIM) aims to solve the problems in advance and adjusting is smooth and easy along the process.

(Contributed by Jayant Keswani,
Director Marketing, Trimble Buildings)