COVER STORY

Statue of Unity Gujarat

The 182 m tall statue is made up of a 25 m high base and 157 m tall statue. The base has high roofs with steel trusses and RCC slabs. The statue is divided into 5 parts – the lower & upper legs, lower & upper body and the shoulder & head.

Salient Features

  • The design life of the project is 100 years.

Construction time

  • 13 months for designing
  • 33 months for construction

Vital statistics

  • 182 m (597 feet) tall
  • The Sardar in a walking pose facing the Sardar Sarovar Dam (that was his vision)

Material used for construction

  • 6,500 tons of structural steel
  • 18,500 tons of reinforcement steel
  • 210,000 cum of concrete

Bronze cladding

  • 1,700 tons of bronze cladding
  • 8 mm thick
  • 550 macro-panels & 6,300 bronze micro-panels

Engineering Features
2 tuned mass dampers each weighing 200 MT to help the statue withstand strong winds & seismic activity.

The steel inside is zinc-coated using hot gip galvanization to enhance its life and withstand corrosion. A viewing gallery at 135 m level that visitors can reach in 34 seconds from the base level.

Unique Features of the Statue

  • At 182 m, it is 100 times bigger that a normal human being
    It is twice the height of the Statue of Liberty
  • At 70 feet, the Sardar’s face is taller than the faces of US Presidents cut out on Mount Rushmore
  • The next tallest statue in the world is the Spring Temple, Buddha in China that is reported to have taken over a decade to construct
  • The statue has been engineered to withstand wind velocities of up to 180 kms/hour
  • The architect is Ram V Sutar, a Padma Bhushan award winner

A tribute to India’s engineering skills and project management abilities
The Statue of Unity, apart from being a symbol of national pride and integration, is also a tribute to India’s engineering skills and project management abilities. We have delivered several projects of national significance and are proud to be associated with building the world’s tallest statue, which is a fitting homage to the Iron Man of India – Sardar Vallabhbhai Patel. Our engineering and construction teams along with the architects, the sculptor, and reputed global consultants, have converted our honourable Prime Minister’s dream into reality in record time. Our commitment to scale, speed and quality in engineering has yielded this desired outcome, which is not only structurally superior but aesthetically appealing as well.” 
S. N. Subrahmanyan
Chief Executive Officer and Managing Director, L&T

Structural Specifications
The 182 m tall statue is made up of a 25 m high base and 157 m tall statue. The base has high roofs with steel trusses and RCC slabs. The statue is divided into 5 parts – the lower & upper legs, lower & upper body and the shoulder & head.

The steel in the statue is in 3 layers: Primary, Secondary and Tertiary. The Primary frames are vertical trusses that interconnected with infill steel members and in turn connected to the RCC cores. These transfer all the load from the statue skin onto the RCC cores. The Secondary steel, that is part of the primary layer, are trusses that carry the load from the bronze cladding connected through the tertiary steel frames. These two layers form the basic skeleton of Statue.

The Tertiary layer is set of steel trusses connected between secondary steel and bronze cladding that bridges the gap between the skin and the skeleton of the statue. Each tertiary steel frame is unique as each bronze panel is unique.

Every joint is unique and that makes the structure extremely complex in terms of design. As it involved Hot Dip Galvanisation, identifying the size of assembly is crucial based on bath size and high accuracy was required to match the profile of statue.

Steel Sections and Erection Technique
Steel section used in the project are basically UB and UC profiles along with plates. The grade of steel used is E350. Two tower cranes each having 8T capacity (at the tip) are used to erect the structure

Overcoming Challenges
For a project of this magnitude and complexity, there were several challenges that the project team faced. Here is one of them.
Due to space constraint, external cranes could not be positioned hence only tower cranes were planned for the entire erection. Till Dec 2018, the entire tower crane hours were used for completing the 2 RCC cores and hardly any steel was erected for the statue by that time.

From Jan 2019, both steel and bronze works were planned simultaneously. As the contractors for both these works were different, sharing of crane hours was very crucial. The cranes were used on all days including Sundays and holidays in 3 shifts for erection and unutilized crane hours for scheduled maintenance.

Ensuring Safety
To construct the world’s tallest statue, one of the biggest safety concerns was of people falling off the edges, falling to the ground through openings, tripping into excavation pits or loose material falling on people working below. Here are three safety measures that went a long way to deliver the project without LTI (Loss of Time due to Injury).

Co-ordination of multi-level activities through a common permit:
With work proceeding simultaneously across multiple work fronts, at various levels, special care was taken to ensure that while people working at lower levels were well-protected from falling objects, those working above were safe and steady on their platforms. 2nd & 3rd levels of PERI (formwork) core wall platforms were given complete fall protection through an all-inclusive permit.

A triumph of teamwork

It is a tremendous achievement by the Buildings & Factories business vertical of L&T Construction. Right from the concept through the entire process of developing the design, the features and characteristics of the statue, the engineering, project planning, logistics, cost controls, were all managed extremely efficiently and reflects a triumph of teamwork. We are proud to have built a monument that makes the country proud and delighted that through this we are honouring a towering Indian personality.
M V Satish Whole Time Director & Executive Vice President – Buildings, Minerals & Metals, L&T

External structural erection
A void area of 6 m was created below overhead safe working platforms extending the full 6 m with catch nets to safely carry out welding activities.

Further, the pre-installed working and intermediate platforms were equipped with aluminium ladders and grab-rope assemblies with an additional platform with a lifting cage ready to be used in an emergency.

Rope Suspended Platforms (RSP) for external welding and management
For the bronze welding activity, the team found that it was very difficult to rescue workmen from the vertical fall arrestor due to the outward slope of the external surface of the statue.

Since cranes couldn’t reach those spaces two RSPs were installed close to each other at the same level of work for work to proceed safely.

Manpower Requirement
At peak times, the work force had 250+ engineers and 4,000+ workmen. A total of 2 million-man hours was consumed for the entire project.

A proposed Cricket Stadium

The design translates the philosophy of creating sustainable buildings along with a contemporary form, thus creating a balance and a global design for the future.

Half of the stadium sites on contoured land thus generating interest through the play of levels and offering a panoramic view of the hills.

The form of the design compliments the natural beauty of the site and its fluidity creates a natural flow within.

Creative group’s role in the project was that of a design consultant and formulating the vision for the conceptual design – from the master planning of the site to the selection of material specification who further collaborated with Populous Architect for this project.

Material Bifurcation
The project proposal is for a cricket stadium and hence the choice of structural materials becomes primary in developing a large-scale design. The structural materials for the project have been carefully selected keeping in mind using advanced but sustainable materials:

Multi Cell Polycarbonate Skylight
Use of multi cell polycarbonate skylight – 16mm thick & 1040 mm wide, fitted on MS purlins, provides the necessary structure while the maximizing the daylight.

Double Skin Stand Up Seam Roofing System
The aluminium roofing system designed and installed to withstand the expansion and contraction forces resulting from an atmospheric temperature range 5 to 45 degrees Celsius. The complete roofing system meets the required thermal (U) performance of maximum 0.32 W/m2K. Compact Laminated Board Wall Cladding

Use of compact laminated board wall cladding is durable and ensures good performance throughout its lifecycle. It also uses 60 per cent raw materials which are recyclable, hence making it environmentally friendly.


We believe that a building can be made sustainable by understanding the nature and choosing the materials wisely, thus focusing on its performance and primarily responding to its ecology and available resources. Our firm has strongly believed in the philosophy that “buildings are more than just a mass of brick and concrete; they are a living organism.” As living organisms evolve, our buildings should also transform with the need and the understanding to create a more sustainable yet creative design. This project proposal was aimed at taking forward this ideology and developing a climate responsive yet contemporary design
CHARANJIT SHAH & GURPREET SHAH
Principal Architects, Creative Group

Architectural Features
It is a general trend and perception that large buildings are biggest guzzlers of energy, but keeping in mind basic design strategies, then it is possible to reduce the energy load and make them sustainable. Solar movement became a decisive factor in orientation of the building and creation of a building envelope to protect against the harsh west sun.

The design is part of a contoured landscape, which provides an excellent opportunity to place the building to provide a clear view of the mountains. The dynamic and fluid form of the design aims at integrating it with the natural surroundings itself, making it a part of the landscape. The proposal also includes a practice field for the players to utilize, thus making the facility a fully functional sports arena.

The entire stadium has been planned in a radial pattern with multiple egress points to enable shortest travel distance. The entry points for visitors, players and VIPs have been clearly defined, thus making the circulation and movement pattern easier. Apart from the stands, a green hill was also designed as a part of the project to provide the spectators a more casual setting towards viewing cricket.

Keeping the approach towards sustainability at its core, the design uses various active and passive strategies to make the project energy efficient and save almost 60 per cent of the energy. Over years due to rapid infrastructure development and building work the open spaces for ground water recharge has reduced considerably. Water table is dropping every year and is cause for immense concern. Grass track with over 90 per cent porosity helps in ground water recharge. Hard surfaces like asphalt and concrete have 95 per cent water runoff and no percolation. Thus, using green grass pavers for parking serve dual purpose of landscaping and ground water recharge.

Adoption of active water saving strategies like – waste water treated on site for irrigation and recycling as flushing water using STP and ETP, use of low flow sanitary fixtures, enable water saving of up to 50 per cent.

Uniqueness
The design translates the philosophy of creating sustainable buildings along with a contemporary form, thus creating a balance and a global design for the future.

Half of the stadium sites on contoured land thus generating interest through the play of levels and offering a panoramic view of the hills. The form of the design compliments the natural beauty of the site and its fluidity creates a natural flow within.

The use of skylights creates a transparency, while the double skin stands up seam aluminium roofing gives dynamism to the large span structure. Further, the use of advanced energy saving techniques and passive design strategies make the project unique in its approach and a model for future such projects.

Madhu Jayanti International Private Limited

The tea blending facility on the national highway near Kolkata evokes an extraordinary contemporary character in an industrial design with hues of grey terracotta. Located in an industrial zone of Kolkata, MJIL represents the ultimate climatological considerations in design through its tilted windows toward south. The cross ventilation inside is enhanced through reversing the position of ventilators in south and north direction. The metal jalis enhancing the venturi’s effect on the southern façade, of the offices located in front area of whole building are nicely reducing the air conditioning load required. Steel has been innovatively used, to construct large span modular construction and the shaded canopy.

Concept
The main focus of the structure was to build a self-sustainable system. All the openings are aligned in such a direction that the interior spaces can experience a natural cooling. The windows at south facade have metal louver at the top and at the bottom in the openings of north and east side facades.

The diffused sunlight can enter through metal (terracotta) jali, indirect illumination can travel a maximum 10 mt. from the external façade. In the upper floor, natural light would penetrate from the north light truss system.

Artificial ventilation based on prescribed air changer is an integrated part of the design. The roofing system allows for hot air escape from the strut of ridge. But in ground and first floor need some mechanical ventilation system for circulation of air. The perforated metal panels at the front facade allow light & ventilation for the front offices area. A water reservoir for water recycling and solar panel promoting renewable energy, were opted being environment concern.

Steel is a material that has been used internally and externally for various iconic structures worldwide. In India and in Kolkata steel is not extensively used, but in the making of the icons such as Howrah Bridge and second Hooghly Bridge, steel had been the preferred choice. The industrial facility of MJIL (Madhu Jayanti International Limited) a tea processing facility has a repetitive module of steel post-beam construction, where, functionality and speed has been the primary drivers of the projects. The vaulted roof and north light with steel perforated front facade adds to a character creating a statement in steel building. The total span of the building is 108m in length and 40m in width. A column grid of 8mx7.2m is continued over the entire building. The focus was driven toward climatic consideration such as ventilation and rainwater harvesting systems. The vaulted roof with north light and angular windows facilitates light and ventilation and a signature iconic design is created in steel”.
Ayan Sen, Principal Architect, Ayan Sen Architects

Steeling Edifice
The industrial facility of MJIL (Madhu Jayanti International Limited) a tea processing facility has a repetitive module of steel post-beam construction where functionality, and, speed has been the primary drivers of the projects. The vaulted roof and north light with steel perforated front facade adds to a character creating a statement in steel building.

The structure evokes an extraordinary contemporary character in an industrial design. The metal jalis enhancing the venturi effect on the southern facade of the offices located in front side. Steel has been innovatively used to construct large span modular construction and the shaded canopy.

Architectural features
The site is situated beside the Kolkata- Delhi national highway. This is the tallest building proposed in that area. Being in such nodal point of the urban scape, the structure itself needs to have a dominating expression. The 110 m long facade with the reputation of few modular openings creates visual symphony.

The surrounding buildings are mostly made in monotonous industrial look. The bright terracotta hue of the panels and the crude concrete texture of the wall is an exceptional composition to attract the visitors’ eyes. The north light truss with a slight curvature over the huge mass is brutally influential. The use of skylight and sunbreaks create an adequate illumination and a pleasant ambience in the interior spaces.

Form Development
The building needed to evoke contemporary characteristics and represent a nodal point on the national highway. The climatological conditions have been kept in mind by changing position of ventilators to north-south direction. The windows are tilted towards south. The metal jalis enhance venturis effect on the south facade of the building.The focus was driven toward climatic consideration such as ventilation and rain water harvesting systems.

Redevelopment of Charbagh Railway Stations Lucknow

The ambitious vision of Honorable Prime Minister Shri. Narendra Modi in transforming railway stations to epicenters and intermodal hubs, giving global integrated solutions to futuristic developments is what has been visualized for the entire redevelopment of Charbagh Railway station.

Ideation
The Mughal architectural marvel of 18th Century from Lucknow, the Charbagh Railway station is on the benches of serious discussions and contemplations on the basis of “Redevelopment” to serve the surge in population and the futuristic requirements in stipulations of facilities and infrastructure.

The term redevelopment holds subdued interpretations in the case of railway station which needs to be very much functional throughout, without any interruption. So the real challenge is to revamp, redevelop or amend the functional infrastructure.

The gigantic horizontal mass encompassing the land, with the heritage and culture reflecting the reverberated visually and holistically with its sturdy incarnations and red renderings.

One of the main railway stations amongst the 10 stations selected by the Ministry of Railways in collaboration, with NBCC happens to be Charbagh, which falls under the Northern Railways. The inception towards the notional redevelopment is subject to partake with the travelers, as an intermodal hub is envisioned to be established in the realistic grounds of Charbagh.

Station Specifics
To withhold the human dynamism in terms of spatial composition, widespread and height of clearance concourse with GI metal double standing seam roofs are planned to be deliberated on the first level, above ground. The concourses will host spaces for multiple functional modules that primarily serves commercial stalls, food courts, sophisticated seating spaces, charging portals, X-Ray scanning zones, kiosks, cloakrooms, ATM, VIP lounge, green spaces and other general spaces.
The concourse being widespread and huge in terms of space, the traipse ought to be eased for which, travellators are included as a mean of vertical circulation. The concourse is connected to the ground level and further below as well as above by elevators, lifts and wide staircases. From the concourses, foot over bridges (FOB) lead ways to exit the railway station. This relaxes the basement arrivals as multiple options to exit the station complex are enabled.

Facets and Geometrics
In the circumferential periphery of the station, six discrete plots have been identified for centripetal neighborhood up-gradation with noble and introspective functional services. The first and foremost pre-requisite, is to elevate the overall morale and standards of the railway station to global superiority in terms of its services, circulatory convenience, materialistic finishing, aesthetic and population holding functional caliber without the tedious rush and push that the orthodox Indian railway stations portray.

The platforms are congested with the flow of people to and from the platforms, in and out of the station. With notions to tackle this collision of passenger traffic, entry and exit points are planned to be bifurcated into two different and separate domains of spaces. The entry of the building is subjected to be through the ground level whereas the parking could relatively go to the basement, so as to enable freedom in the drop off services in the ground level.

The current access points to the railway station would be comprehensively made for the approaching crowd, as it by default leads to various platforms and ticket counters by the parent planning. The arrivals are equally mighty in terms of the populace, hence they are taken to the basement, thereby defining the exit. To the South of the existing railway station, lies the streak of railway tracks. Further beyond the tracks, plot 2 has been formulated to serve the function as a rear entry edifice to the Charbagh station.

This holistic and broad visional version of approach with sustainable, future adaptable and people user-friendly measures to the Charbagh railway station, undeniably garner public appreciation with active participation. Such advanced architectural interventions are very much in command to cater to the future needs of the rapidly developing population and subsequent global metaphorical expressions of growth.

CHARANJIT Shah and Gurpreet Shah
Principal Architect, Creative Group

The rear entry building is connected to the concourse of the main building through FOB and concourse above the rail level. The metro station is also connected to the primary concourse that is behind the existing Charbagh railway station concourse and FOBs. This facilitates passengers travelling through metros to directly enter the railway station without taking the additional pain of stepping onto the road to cross and reach the railway station. An FOB provisioning change in levels with a connective concourse enhances the passenger movement expeditiously. Alongside, on other neighboring plots that are identified as plot 3, building complexes with commercial spaces, showrooms, corporate offices, hospital and different range of hotels are visualized to be designed as a part of redevelopment agenda. These services are identified to be the most indigenous necessities of public interest.

The commercial spaces feed and quench the needy, wherein, the hospital helps the defendants from not being forced to travel into the city in search of medical services. Incoming patients from other regions would be benefited with a hospital about the railway station. The corporate offices nevertheless comfort the floating population of workforce floating into the city of Lucknow, by providing ease in access to the workspace within the periphery of city’s significant railway station. The plot 4 serves as residential quarters for the railway staffs, alongside hotels and accommodation facilities. Plots 5 and 6 nonetheless offer built spaces for similar functions as of the building on plot 3 does, by mean, corporate offices, commercial shopping corridors, showrooms, etc. All these plots are cohesively connected through concourses above the rail and road levels, hence relieving the pressure on roads by pedestrian interruptions as well as vehicular ruckus.

The basic drawings are prepared in AutoCAD after conceptualizing it with hand sketches for the basic idea, the design is developed in BIM interface like Sketch up where each, and, every part of the drawings responds collectively. Also, the animation and renders are being prepared in 3dsMax.

Learnings
In simple dictums, a new and noble set of built attachments to the existing railway station unit, not only advances to quench the needs of future but also defines and magnifies the overall morale of the city fabrics. The concept of sustainability is substantially overlooked to reduce the carbon footprints to meet ends in the future, hence lush green spaces are gushed into various regions of the intermodal hub.

Plantations in the basement serve aid to the fumes let out by vehicles. Similarly, trees and plants are subjected to be plotted in and around the glass, steel and concrete structures. Solar panels could serve the basic electricity dependence of the multifunctional concourses, while potted plants can nourish and create a holistic aura in the waiting lounge.

Fact File

Client: RLDA, NBCC
Architect: Creative Group
Consultant: Ahluwalia Developers and Contractors
Steel Tonnage: 9968 MT
Status: Ongoing

World Center-3 Ahmedabad

Ahmedabad is seeing a rising trend for good office real estate assets, due to rapid employment generation and eminent possibility of the first REIT listings. With increasing traffic woes, distance is becoming an avid concern for businesses. When a company chooses to pick up a good office location an hour away, it sees a lot of attrition. So, a decision was made to provide a world-class business center in the city itself.

Thought Process
One of the biggest advantages of World Center is its strategic location i.e. on Sabarmati Riverfront, an upcoming business district in the center of the city. It also holds its proximity to Airport, Metro and business class hotels making it a hot-spot for business houses to station their offices in an International standard business center.

The focus is always on the quality of development and growth by innovation. The next priority is to minimise the impact on the environment, and, reduce the wastage by encouraging eco-friendly initiatives. In fact, World Center is a Green initiative by Savani Group, and it is IGBC Platinum rated first Green Building in Gujarat preserving natural reserves and substantial cost savings.

The imperative effect
The project team’s values are the foundation to their projects. The same has also helped them earn the most accolades till date and they strive to keep improving for best. The other partners ADS Architect, JLL, Setu, Infra, PDA Associate, Manisha Construction, Savani Infracon LLP on board also bring along the same values to accomplish the mission.

 

World Centre 3 is the unique project in the commercial
hub of the city of Ahmedabad – Steel structure, all around facade,
platinum rated Green building, located on Riverfront is the few special features. Being located at ashram road and surrounded by commercial spaces,
space constraint, traffic congestion was the big challenge of construction

Vishal Sheth
Partner, Savani Group

Mentation
The client believes in designing and creating lifestyle products rather than boxed spaces. Winston Churchill has also said, “We shape our buildings; thereafter they shape us.”

For them, the architectural brief for World Center was of utmost importance, as it plays a vital role in documenting the dream project’s outcome and deliverables. It was clearly one of the ambitious projects with every inch of space designed to give a feel of spaciousness. The architects were briefed to inculcate premium executive’s minuscule needs of work life and ensure the ease, comfort and functional abilities in working space.

Overcoming Challenges
Being in business for so many years and having all types of seasons, the team was prepared for challenges in this project, too. The dream project, World Center, had different sets of challenges especially working from the center of the city with almost no working space.

It was decided to put the labor and material resources in nearby residential bungalows to avoid disturbance on the functional roads. Also, due to the crowd in weekdays, the team used to cast raft during weekends. Having said, all the challenges were overcome in the most efficient way ensuring safety and security for all those involved. The journey of how it was built is also important to ensure everyone involved in the making is happy to give in their best to the vision.

Using Steel
Steel is the world’s most trusted construction material with great flexibility and versatility which makes it easier for designers, developers, and architects to turn their visions into reality. Steel structures are strong, sustainable, and of course, it is 100 per cent recyclable.

There are exciting newer trends in the industry that will likely impact the steel market in a positive way owing to technology and connectivity Savani Group always considers emerging trends into account, as they continue to develop quality lifestyle assets and it is a belief that steel’s longevity, versatility and sustainability will only lead to more from our community to use in more projects, not less. The client is glad to be the leaders in bringing in newer trends in Commercial Reality for the Gujarati businessmen community. For World Centre 3, steel was acquired from one of the best and finest steel providers who hold a remarkable place in the market.

Uniqueness
World Center 3 will mark a new horizon in the commercial realty sector of Gujarat. With its presence in the upcoming Central business development zone of Ahmedabad, it will emerge as a landmark in the new downtown of Ahmedabad in the scenic riverfront. To know about the unique features of the World Center, one should, step in and find himself into a whole new professional arena!

World Center is a class apart for all working professionals. The office spaces are well equipped with all modern amenities and sizes starting from 4800 Sq. Ft. and above.

 

FACT FILE

Principal Architect : ADS Architects,Ahmedabad
Structure Consultant : Setu Infra,Ahmedabad
MEP Consultant : PDA Associates
PMC : JLL,USA
Civil Contractore : Manisha Construction
Steel Fabricator : Tender in process
Client : Savani Group

Atmosphere, Kolkata

Atmosphere is conceptualized as an ultra-luxurious residential project with 80 villas and with a vision that each villa should be unique. The structure is an icon for its overall vision, the architecture expression and the engineering determination. Deya enthralls that moment of inspiration, and it make the dream float through the cloud to its destinations, into an amazing atmosphere

Setting up the squad
M N Consultants role was that of a structural engineer. Along, with concept designer web structure they had the responsibility of transforming the owner’s dream into working reality. There were various aspects of design like mep, architectural, infrastructure which had to be worked on with, and, create a structure which is suitable for all their needs and safe in all aspects of design.

Structural Aspects
A B+G+37 stories high rise condominium with ‘Deya’ the connecting bridge at a height of 100m from the Ground level. The magnificent hanging sculpture is intended to look a floating cloud between the peaks of the two towers. The structure will span more than 320 feet in width, 55,000 square feet of usable space having a silver lining façade featuring numerous kinetic discs. It comprises more than 1,500 steel sections with a total weight of 2340 tons, assembled 100 metres above the ground.

The structure had to straddle between two towers in a combination of a “beamlike “and a “catenary” system. The primary challenges facing the structural system includes fundamental issues of safety and serviceability, as well as the critical issue of constructing such a large structure some 40-floors up. Limiting and controlling the movements of the towers at the roof levels, where, the cloud structure is supported, whilst maintaining serviceability of the towers and the sky-bridge under seismic loads and the high wind forces that prevail in Kolkata have been the primary structural considerations.

Challenges
The primary challenges facing the structural system include fundamental issues of safety and serviceability, as well as the critical issue, of constructing such a large structure some 40-floors up. To make 100 meter. bridge move independently without affecting behaviour of the building during the lateral movement was the biggest challenge. The second big challenge was to design a foundation system to cater to such huge lateral load.

 

Deya’ a bengali word used by the famous Nobel Laurette Rabindranath Tagore meaning heavenly cloud, and so is the name of the bridge, which is connecting the two towers in the sky in the form of a cloud. It’s a Great creation by the Architect, and not only an engineering marvel but a piece of art amidst clouds at a height of 110m. The concept of the structure behind this piece of art is also a unique in nature. The state of the art design and the concept of base isolation is truly a piece of engineering excellence. The fabrication and erection of the bridge had to be very precise and done with the help of state of the art technology. As a structural designer, guided by the Master Dr. Hossein Rezai-Jorabi, it’s an unforgettable and probably a lifetime experience for me.
Utpal Santra, Managing Director, M.N. Consultants Pvt. Ltd.

Specifications
The structural system is a steel space truss. The space truss is made-up by several distinctive components/hierarchies, each performing specific tasks:

  • Longitudinal Trusses: span between the two towers, and, form the main spine supporting the cloud structure.
  • Transverse Trusses: span between the longitudinal trusses, and, cantilever from them to form and support the actual cloud floor structure.
  • Floor Diagrid: provides lateral rigidity to the floor structure.
  • Horizontal Arches: control lateral movements of the cloud structure.
  • Crown: form the support for the floors and the roof at the ends of the cloud structure over the two towers.
  • External Diagrid: binds all the other components together to ensure they all work in unison.

 

The name Deya literally means the cloud, a cloud is a cloud, light and heavy at once… Deya has been visualized as a sky club seemingly floating between the two tall towers of Atmosphere. The designer’s challenge was to build something as solid and stable and yet be very light. Deya spans between two towers for a distance of 96 M, 72m being the effective span that measures between the two bearing supports. The longitudinal trusses forming the main span, further with transverse trusses, floor diagrid, horizontal arches, roof arches, crown, and, finally the external dia-grid which binds all these components together to ensure that they all work in unison. There are other five aspects of the project which when put together with the sky bridge make this whole thing rather complex or rather sophisticated structure. Firstly, structure of both the towers of Atmosphere needed a strong base to hold the sky bridge in any kind of weather. Secondly, using of UC steel sections of 356x406x1086, having thickness of 125mm and unit weight of 1086 Kg/m. Thirdly, there was a potential risk in movement of Sky Bridge. Every movement was monitored during lifting work. Additionally, Train gauges were proposed to provide at the tension supports. Fourthly, during lifting, vertical deflection were monitored and checked and manipulated with analytical results. Finally transferring the entire Sky Bridge load to 4nos Eradiquake Isolation Bearings placed two at each tower. Constructing Deya makes one realize the flexibility of the steel. From the lifting of the Sky bridge belly to erection of different layers; and finally completing the external façade elements including the fixing of the kinetic discs on the Deya skin, it has been a continuous challenge. Working and being a part of it has been an absolutely unforgettable, unique and extremely enriching; an enthralling experience
Krishnendu Ghosh, Deputy General Manager, Forum Projects Pvt Ltd

 

Exclusivity

The features of the project are:

  • The architectural design intent of the project.
  • The structural design itself has been absorbed to define the architecture.
  • The bridge connecting two 37 storey tower spanning 100 meters build with 2340 Mt of steel.
  • The bridge is not just a walkway it houses four floors which is unique in itself.
  • The tower has big cantilever terraces which was also a challenge to design and built.
  • The base isolation done using special bearing below the bridges.
  • The concept of bridge sitting on base isolation at the height of 120 meter.
  • Limiting and controlling the movements of the towers at the roof levels where the cloud structure is supported, while maintaining serviceability of the towers and the sky-bridge under seismic loads and the high wind forces that prevail in Kolkata have been our primary structural considerations.
  • The way steel structure has been designed with combination of longitudinal and transverse truss along with binding by floor diagrid which is itself one of its kind.
  • The no of bolts, joints that have been provided in this project is really a big number to handle. Total number of welded joints = 1,090 Total number of splice joints = 1,317 Total number of bolts = 30,000

 

Fact File

  • Client: Forum Projects 
  • Architect: Arc Studio, Singapore & Practice Design Pvt. Ltd.
  • Structural Consultants: Web Structures & M.N. Consultants Pvt. Ltd.
  • Contractor: L&T
  • Steel Fabricator: Eversendai
  • Steel Tonnage: 2340MT

 

 

Guwahati International Airport, Assam

The project encompasses a new Integrated terminal building of Guwahati International Airport, an upgrade to the existing infrastructure. A global tender for the project was floated by Airports Authority of India, and DFI in collaboration with Aecom succesfully bid for the same. AAI envisioned the terminal to be an establishment reflecting the aspirations of the place and mirroring the local context. The desired outcome was envisioned to be a terminal that reinforces the Guwahati appeal, a creation that combined contemporary elements with an international appeal to produce a contextually relevant output.

Ideation
At Design Forum International, designs are aimed at creating memorable and awe-inspiring experiences for the users. The Guwahati International airport is conceptualized in a similar vein: the intent is to trigger moments of discovery and togetherness, enhancing user engagement. DFI also believes that it is important to be contextually reverent. The design, therefore, is infused with the flavours of Assam.

The design solution emerges out of the intent to soothe frayed nerves and tired bodies, and to create an environment that evokes memories, stirs wonder, and rekindles pride and a sense of belonging. Designing an airport presents an intriguing challenge; aviation is one of the most complicated industries in the world and runs on incredibly smooth logistics. One has to contend with enormous functional demands, and almost military-level precision.

The architects did not want to restrain themselves to just fulfilling the requirements; they yearned to imbibe the design with an identity – a lingering, almost-haunting memory of the time spent within. It is from this pull and push of forces that a thought emerged: there was a need to create spaces that would involve and stimulate, and not just deliver and facilitate.

Steeling Structure
Steel was the prime choice due to its numerous advantages over other construction materials. Steel provides a much higher tensile, and, compressive strength as against other materials. In case of huge buildings like airports, where huge spans of uninterrupted spaces are a must, steel is the only viable material of choice in the Indian context.


The Indian aviation industry spearheaded by Airports Authority of India is currently registering a 15-20 per cent Compound Annual Growth Rate. Contributing substantially to the annual growth, Guwahati International Airport registers an annual growth of 36 per cent, which is double of the national growth. The addition of a new international standard terminal will only add to this growth by supporting the overflow and paving way further for user expansion. The new airport serves as the second most important entry and exit point to the north eastern India after Kolkata. On completion, it will be able to exponentially increase its operational load, thereby handling the north east segment all by itself. In the longer run, Guwahati International Airport will be instrumental in connecting the north east with international destinations across the globe, especially Asian nations and the south west sub continental countries.
Anand Sharma, Principal, Design Forum International

Uniqueness
Conceived as the iconic Icarus: The epitome of the human urge to fly. The form of the structure takes inspiration from Icarus – the mythological figure who dared to fly. The majestic centrepiece is symbolic and looms over the departure concourse, its arms outstretched as it reaches out to the skies. The floating form doubles up as the canopy for the drop-off zone.

Origami: An art, an expression. Few things straddle the realms of art, physics, and sculpture, as origami does. The childhood memories of flying paper planes, zooming towards the heavens, are reminiscent of individual craftsmanship. While designing, Origami served as a guide to the architects – a companion and a tool as they delved into the evolution of form. Before they knew it, however, the idea dominated the design completely: it finds expression in the terminal roof, the flooring patterns, the column cladding, the theme walls, and even the signage design.

Craft Village: Immersive and engaging. India is a land of diversity: every nook and corner of the land is packed with mysteries and local delights. The airport recreates this experience for the travellers, extending it beyond books and handicraft emporiums.

This enhances engagement, making travellers a part of life at the airport. Spaces have been allocated for the artisans to sit and produce right at the airport, encouraging interaction with visitors. Engaging the craft, the craftsman, and the visitor, in one experience altogether, the crafts village augments the shopping and retail experience for the traveller.

Indoor forest: Wish you were here. Coming out of the plane, the travel weary eyes look for some solace, a relief from the mass of humanity that engulfed them on the plane. It is here that one views an oasis of rich river-basin rainforest from the corner of the eye, and out comes the yearning to be a part of it.

Lo and behold! Wish granted – The visitor is positioned within a 90-feet high indoor rainforest, which needs to be navigated before being reunited with the luggage. The rainforest doesn’t let one just hurriedly pass through; passages that zig-zag through this space bring forth vistas and wonders at every corner.
Craft Walls: Is it an airport or a gallery? The craft walls have been conceived as a canvas for current and future trends: they display innovative products and artefacts. The Namaskar Atrium is a massive double-heighted space that creates an experience for the inbound visitor, with its walls adorned with the art and craft of Assam. The Baggage Claim hall wall is an exercise in modularity with origami aluminium panels that derive inspiration from the hilly terrain of the North-eastern states.

Tea-gardens: On an airport, where else. The tea-gardens are a mark of reverence to the context and serve as an inspiration for landscape design. They are positioned at the front yard along with a water cascade. The landscape weaves a story of its own and clings to the departing and arriving passengers as they walk through it before boarding their pick-up vehicles. The drive up to the departure level is reminiscent of the first climb up a mountain road, after the tiring and relentless plains. The car zooms up as the plains give way to rolling earth-berm greens.

Materiality: An architect’s best friend. To enrich materiality, glass was selected as the palette of choice for the façade – GFRC wraps around the façade’s tricky and smooth wide expanses, facilitating day-light penetration and visual uniformity.

The use of terracotta tiles references the architecture of fort-like citadels and imparts stability. Terrazzo flooring has been employed in the interiors for its versatility and playfulness, whilst the use of granite ensures steadiness. Aluminium origami panels endow relief and sintered stone is used for wall and column cladding.

Geometrics
Few things straddle the realms of art, physics, and sculpture, as Origami does. The childhood memories of flying paper planes, zooming towards the heavens, are reminiscent of individual craftsmanship. While designing, Origami served as a guide to the architects – a companion and a tool as they delved into the evolution of form. Before they knew it, however, the idea dominated the design completely: it finds expression in the terminal roof, the flooring patterns, the column cladding, the theme walls, and even the signage design.

Designing Tools and Experience gained
BIM (Building Information Modelling) software, namely Autodesk Revit et.al.

At the altar of the land of the mighty Brahmaputra and maa kamakhya devi, the new Integrated terminal building at Guwahati International Airport is an ode to the ancient yet reinvigorated spirit of Assam, the Seven Sisters, and our own Incredible India. The construction of the project started in Jan 2018 and is slated to finish by Jan 2021.

L&T Business Towers

L&T Realty, the real-estate development arm of Larsen & Toubro has a presence in Mumbai, Bengaluru and Hyderabad. Its international presence includes sales and marketing representatives in Singapore, Dubai, UK and the USA.

L&T Realty is committed to creating landmarks of excellence, and aims to enrich people’s lives through sustainable developments. It’s vision is to become the most respected real estate developer of the country by building on its execution leadership and by honouring the dual commitments of quality and delivery timelines. L&T Realty’s portfolio consist of 59 million sq. ft. of residential, commercial, retail and transport-oriented development.

Approximately 25 million sq. ft. is a commercial, retail and transit-oriented development which has a direct link with the use of structural steel.

To make any project successful speed, quality and cost are the three major attributes. When we talk about speed and quality, we believe that there is no match to structural steel as a primary construction material, and as far as cost is concerned, economies of scale (i.e. enhanced usage of structural steel) will certainly help in matching the cost to the conventional RCC construction.

Structural steel also becomes very much important keeping in view the recent changes in public policies. For example, the introduction of MAHARERA (real estate regulation act) ensures that the developers not only deliver on time, but also quality and cost aspect of the product are taken care of with 100 per cent transparency.

In a nutshell speed, quality and cost are three attributes which are going to govern the future of building construction industry in India, and it is safe to trust that the maximization of structural steel consumption will take us closer to the achievement of our business objectives.

L&T Realty realize that before starting conceptual design of any project, the developer should direct the Architectural Consultant, Structural Consultant and Services Consultant to start working closely with the project manager to ensure that the cost, time and quality aspects are maintained during the entire lifecycle of the project.

Let us illustrate with an example. If we look at cost bifurcation of any building project, we realize that approximately 70 to 74 per cent of the total cost is attributed towards core, shell and MEP works. The remaining 26 to 30 per cent of the cost is associated with finishing. We also understand that approximately 85 to 90 per cent of the cost is finalized on design table.

If we co-relate cost, time and quality as variables, it is understood that if we take charge of this 70 to 74 per cent of the cost to achieve desired speed and quality, the same will offer a lot of relief to remaining 25 per cent of finishing work which can be worked out in close co-ordination between project manager and the architectural consultant. This is one reason that Larsen & Toubro have chosen to proceed with development of in-house design teams.

L&T Business Towers
L&T Business Towers are located at the junction of Saki Vihar Road and JVLR (Jogeshvari-Vikhroli Link Road) which is popularly known as gate number 3 of L&T. This project is being constructed for the captive consumption of Larsen & Toubro. These two towers are exclusively designed by Larsen & Toubro and are being constructed by L&T Construction which is the largest construction company in India. These buildings are designed and constructed as per the LEED Gold rating norms.

These buildings consist of:
• 1-basement in RCC with 2-podiums,
• 1-stilt & 16-typical floors in composite structural steel.
• Floor plate area is 30000 sqft.
• Column free space is around 13m.
• Floor to floor height is 4.2 m

Evolution of Design – RCC to Composite Steel
We started designing business towers as conventional RCC buildings. Simultaneously, the soil investigation work was taken up by FUGRO. They investigated 24 boreholes along with the geophysical studies of the plot. As we entered design development, we started understanding the following constraints:

  • The senior management of L&T gave us a challenging task of completion of this 11.25 L sq. ft. BUA building with fitouts within 27 months
  • The FUGRO investigation revealed that Basalt of very high compressive strength was available at very early depth of 2m from the natural ground level
  • In RCC structure it was also realized that reinforcement cutting, bending & placing in vertical elements is going to consume considerable time.
  • L&T’s Powai development is in the close vicinity of the Mumbai airport runway & therefore the building height is restricted
  • Looking at the plot geometry it was clear that the site was a logistics nightmare.

 

 

  

To summarize the change in design from RCC to composite steel
with concrete filled tubes is helping L&T Realty to achieve
speed & synergy in project and will ensure the delivery of this G+16 storey
high rise commercial tower within a record time of 27 months.

Ankur Jadhav, Project Manager, L&T Realty

Overpowering Restraints
The bore logs revealed the presence of high-density basalt rock at very early depth of 2m. We realized that we have to excavate approximately 1.5lakh cum of rock which means approximately 22000 truckload of hard basalt rock.

20-excavators started working on project site and when we realized that the same is not helping the purpose, then controlled blasting was deployed to expedite the excavation process. Further, to protect the soil on one side & the only available route for logistics on other side, we had to carry out shore protection work using 1500 micro-piles which was successfully completed in 90days.

We started excavation activity in January 2018 and the building is to be inaugurated latest by March 2020. Keeping in view the nature of rock, the monsoon & statutory constraints we realized that no matter which technology we use for excavation the same is going to consume at least 7 to 8 months for excavation. This challenge was understood immediately after geotechnical investigation was completed in September 2017 and we started discussing a change from RCC to steel structure; however, it was a little early to conclude and move towards Steel structure.

It was towards early October 2017, when we concluded that we are not going to get any additional time to complete the project and no matter what the buildings must be up & running by March 2020, we seriously started thinking about the steel building option to overcome the time delay in excavation.

L&T design team started working with steel framing along with metal deck slab which resulted in considerable time saving of approximately 3.6months. This resulted in slab cycle time of 7 days. We also opted for triple height concrete filled tube columns (CFT columns) which further helped to reduce the time spent on conventional RCC columns and walls. The prefabricated steel framing also reduced site activities to greater extent. Most importantly when we were carrying out our excavation simultaneously the CFT columns and beams were getting fabricated in shop.

Concrete-filled Tubes – Engineering Marvel in Composite Steel Design
As mentioned earlier, RC design was leading us to a time-consuming reinforcement cutting, bending and placing in columns and RC beams. We introduced RC beams in the system keeping in view the lateral drift requirements stipulated in NBC2016.The large depths of RC beams for 13m span were further adding difficulties in achieving floor to false ceiling height.

In order to resolve these issues, we opted for concrete filled tube (CFT) columns with internal steel ribs which completely eliminated the need of reinforcement in columns. These columns were designed in such a way that these columns can be erected for a height of three floors. The core wall of building was checked for slenderness and we allowed the core jump form for three floors as well. This enabled our construction team to proceed with three slab leading to expedited construction activities.

As compared to large depth RC beams we shifted to relatively low depth steel beams. With the issuance of NBC2016 it has become difficult to design the flat slabs in RCC buildings. The steel deck slab not only provided us with a solution in this regard but also, we could eliminate the use of horizontal formwork in these buildings. Similarly, the use of CFT columns eliminated the use of formwork for columns. The jump form offered us relief on slab cycle time as well. The simple beam to column connections also enabled us to expedite construction activities.

Flexibility for Services Routing
13m span was suggesting large depth RC beams which also created a problem for routing of services in these buildings. The introduction of steel beams not only reduced the beam depth but also provided us with an opportunity to introduce castellations in steel beams which offered a lot of flexibility for services routing.

Overcoming the Logistics Challenges
The plot geometry was a logistics nightmare, having a long tail and most of the plot where the buildings are located provided hardly any space for material storage, enabling works and other site related activities.

The steel structure is being fabricated in shop and transported to site using “Just-in-time” principle which eliminates additional space requirement for storing steel members. Use of composite steel structure also reduces the requirement of reinforcement which results in less space requirement for storing reinforcements.

Steel structure also eliminated the requirement of formwork for beams/columns/roller deck slabs, thus eliminating any need for space provision for formwork as well as labour for formwork.

The time consumed in activities like cutting, bending and placing reinforcement, concrete curing, fixing and removing formwork was brought down to such an extent that this not only provided a saving in time but also allowed us to plan site logistics in a disciplined and organised manner.

Initiatives to Achieve Speed & Synergy
Following are the major initiatives which helped us achieve desired project duration to meet our business objectives:

  • Structural steel fabrication in shop during excavation and foundation casting activity at project site ensured that we recover the time lost in excavation.
  • Use of CFT columns with no reinforcement and 3 floor erections in one go opened the construction of 3 floors simultaneously resulting in considerable saving in slab cycle time.
  • Simple connection designs and details ensured the optimization of construction time.
  • Pre-fabricated steel beam with coordinated services cut-outs provided saving in time for MEP work.
  • With the use of Intumescent paint over steel column we could get rid of column cladding work which also reduced the finishing timelines to certain extent.
  • Optimization of site related activities which are related to reinforcement cutting, bending, placing, formwork, mobilization etc. offered us great deal of time saving.
  • In addition to this the skilled manpower requirement reduced drastically due to mechanised construction.

The true success of this project is in the state-of-the-art composite design facilitating large column free spaces along with the optimized floor to floor height, speed of construction & superior quality of final product as formwork is eliminated. The quality of work during the construction and the safety standards followed are typically in line with what L&T is known for.

(Contributed by Sunil Godbole, Senior DGM – Structural Engineering, L&T Realty)

Coleroon River Bridge, Tamil Nadu

The location of existing bridge is in the northern gateway of Trichy city. The bridge connects Samayapuram toll gate with Thrivanalikovil and Srirangam towns. The intensity of traffic through the existing narrow bridge is inadequate for present day traffic.

The heavy vehicles from Trichy to Samayapuram, Turaiyr,Musiri, Namakka, Alem, Lalgudia and Ariyalur are diverted from Trivanaikovil to NH-45 four lane bypass pads, as the existing bridge is narrow and weak.During peak hours, passengers find it difficult to cross the bridge due to heavy traffic congestion. This existing bridge serves as the means of transporting agricultural products to Trichy city from northern districts. Hence,reconstruction of the bridge is very essential for road users for free flow of traffic.

Specifics
The bridge is across River Coleroon at Srirangam TamilNadu. The total length of bridge is 792.0m. It is 4-lane bridge with footpath on either side, with total width of 21.45m. The span arrangement is 24 spans of 33m.The superstructure is with Bow String Arch, with partially prestressing (for tie member) substructureportal frame, with twin piers over pile foundation with 1200mm dia bored cast-in-situ piles.

Geographics
Trichy is the fourth largest municipal corporation in Tamil Nadu,and, the fourth largest urban agglomeration in the state. The city covers an area of 146 Sq. Kmwith a population of 7,52,066 in 2001.It is rated to be one of the fastest growing cities in TamilNadu. During, the last couple of decades, the life style of people, and their commuting habits have undergone radical changes, due to steep hike in the cost of urban land in Trichy, and, the revolutionary changes in major engineering equipment manufacturing, high-pressure boiler manufacturing steel plant and chemical industries.

During peak hours, passengers find it difficult to cross the bridge due to heavy traffic congestion. Moreover, Sriranga Temple – Pilgrims and tourists come to this, and, it is considered as the most important place in Trichy District. Sincethese towns are located on the banks of river Kaveri all the developments, settlements have been concentrated between this river and around.

 

The project bridge is across river Coleroon at Srirangam Tamilnadu. The bridge location is very close to ancient SriRangam temple, and, in view of its attention was paid to aesthetics of the bridge structure, Bow string Arch was selected accordingly. Most of the bowstring arch bridges in our country is with 2-lane & footpath. This is one of the widest Bridge with Bow String Arch.The analysis of portal frame for substructure, carried out with Staad Pro software for various loads and combinations, including wind & Seismic as per IRC Codes.The piles were analysed for vertical forces and horizontal forces with Soil Structure interaction, considering scour levels, with Staad Pro analysis.
B V NAGESH, Principal Consultant, Nagesh Consultants

 

The proposed bridge is connected to important places like Rock fort, Srirangam, Renganather Temple, Thriruvanaikovil, Akilandeswari etc.

Approach Methodology
Stage – I  : Field Investigation:
• Conducting Topographic Survey
• Soil Investigation as per NIT.
• Conducting Traffic Survey as per NIT
• Identifying the Utilities.

Stage – II : Detailed Analysis and Designs
• Preparation of GAD and discussing with the authorities for approval of the same.
• Detailed Analysis of Super Structure and Sub Structures.
• Design of Super Structure, Substructure and Foundations as per IRC Codes and specifications.
• Preparation of Detailed Drawings.
• Preparation of Detailed BOQ and cost estimates.
• Preparation of Tender documents.

Structural System of Bridge
24 No of 33m c/c spans are proposed to suit the Existing Pier location and Length of the Bridge. The overall length of the Bridge from Abutment to Abutment works out to 792m.

Super Structure
Super structure is proposed with Bow string arch girder. C/C distance between expansion joint is 33m, and effective span is 30.75m. Tie members are with cast in situ post-tension girder, other elements are cast in situ RCC member.

Entire super structure shall be cast and cured before the post tensioning operation. Staging provided for tie member shall be removed only after stressing operation.The deck system is analysed using STAAD-PRO software with 2 models i.e., for deck slab as continuous beam of width3-D analysis for remaining elements of super structure.

The Pot cum PTFF bearings are proposed as per IRC: 83 part III. The Jack locations are proposed at 0.75m from C/L of bearing below the end cross girder, and, the load combinations are as per IRC: 6-2010, and, design is carried out as per the guidelines of IRC: 112-201, and, references are made to Euro code, IS codes.

Deck Slab
The slab is supported on cross beams, which are 3.075m apart. 11 cross beams are proposed including 2 at the bearing locations which will rest on the tie beams spaced at 17.25m. Hence, the slab panel size is 3.075 x 17.25, essentially one-way slab. The slab is idealized as one-way continuous slab of 1m width and analysed using Staad Pro adopting effective width of dispersion method.
Codes & Standards
The design of various components of the bridge, in general are based on provisions of IRC/IS codes

IRC: 5 – 1998: Standard Specifications and Code of Practice for Road Bridges, Section I – General Features of Design.

IRC: 6 – 2000: Standard Specifications and Code of Practice for Road Bridges, Section II – Loads and stresses.

IRC: 112 – 2000: Standard Specifications and Code of Practice for ConcreteRoad Bridges.

LOADING:
Dead Load (DL)
The unit weight for Dead Loads calculation has been considered by adopting unit weights as per IRC: 6 – 2000(Standard Specifications and Code of Practice for Road Bridges, Section II – Loads and Stresses).
1) RCC -25 KN/m3

Super Imposed Dead Load (SIDL)
1. Wearing coat -2 KN/m2
2. Crash barrier -7.75 KN/m
3. PCC in footpath/median filling–22kN/m3.

Footpath Live Load
As per Cl: 206.3, IRC: 6-2010 – 5 kN/m2
Vehicular Live Load (LL)

As per IRC: 6, deck slab is analysed for the following vehicles and whichever produces the severe effect has been considered in the design. Following combinations are used:
1) Three class A vehicle.
2) One 70R tracked + one classes A vehicle.
3) One 70R bogie + one class a vehicle.

Transverse Analysis of Deck Slab
The deck slab is idealized as one-way slab of 1m width supported over cross girders supports are assigned at cross girder location panel size works out to 3.075 x 17.25.

Dead load analysis:
Dead load analysis is carried out for 3 cases:
At footpath location.
At Median location.
At Carriage way.

(A) At Footpath Location:
a) Self weight of slab = 0.275 x 25 = 6.875kN/m2.
b) Super imposed dead load:
i) Due to hand rail – 7kN/m
ii) Due to PCC filling in footpath = 0.25 x 22 = 6.16kN/m2.
iii) Footpath live load = 5kN/m2.

(B) At Median Location:
a) Due to Self weight = 0.275 x 25 = 6.875kN/m.
b) Due to median filling =0.30 x 22 = 6.60kN/m
= 13.475kN/m

(C) At Carriage way:
i) Due to Selfweight = 0.275 x 25 = 6.875kN/m2
Due to Wearing Coat = 2.00kN/m2.
= 8.875kN/m2

Analysis for Vehicular Live Load

Vehicular live load analysis is carried out using staad pro with moving load option for following vehicles.
1. Class A vehicle.
2. Class 70R wheeled.
3. Class 70R Tracked vehicle.

Post processing is carried out for 3 supports and 3 spans for above vehicles and reinforcement detailing is carried out for critical values.

Effective width of dispersion

For interior span beff= α x a (1-a/l) +b1———Formula 2

b1= 0.25+2×0.075 =0.40 ( Width of dispersion parallel to support upto the top of slab.
α =2.6, As per clause 305.16.2 IRC: 21-2000, for continuous span with l/b>2.
a= C.G of the load from nearest support.
Calculation of ‘a’

Vehicle moved on the deck with an increment of 0.25m. Load position with respect to critical value of bending moment both for support and span is fond and C.G of the loads corresponding to this location is found .and then C.G of the wheel loads distance from nearest support is taken as ‘a’ specimen calculation for all the 3 types of vehicles are explained in the following.

Impact Factors and Partial Safety Factors:
Impact factor is considered as per cl.208, IRC:6-2010.Following load factors are considered for structural design, IRC:6-2010
i) Dead Load and SIDL except W.C = 1.35
ii) Wearing coat =1.75
iii) Footpath live load = 1.50

Internal Cross Girder
Concrete Grades and Reinforcements:

Concrete: –
For RC Deck Slab (M – 40)

Reinforcement: –
HYSD bars (Grade Fe – 415) conforming to IS: 1786 are provided as reinforcement.

Clear Covers: –
The minimum clear cover of 40 mm to reinforcement has been considered indesign as the site is under “moderate” exposure condition.

Bearings
POT cum PTFE Bearings are proposed as the order of loading is high. 4 bearings are proposed per each span with articulation of Fixed, Guided and Free Bearings.

Sub Structure
Turning pier substructure system was proposed. The twin pier system was analysed for following loads and load combinations –

1) Dead load from superstructure.
2) Live load from superstructure.

Following vehicular loads were considered
i) 2 class -A
ii) 4 Class A
iii) 70R vehicular + 2 Class A
iv) 2 – 70R vehicles

Vehicles on one span & both span was considered.

3) Longitudinal forces as per IRC:78.
4) Wind load.
5) Seismic forces.
6) Water current forces.

Load Combination

  • Load comb 99 dl+ll on one span with if+bf+ff.
  • Load comb 100 dl+ll on both span with if+bf+ff
  • Load comb 101 dl+ll on one span without if+bf+ff.
  • Load comb 103 dl+ll with if+bf+ff+wind on ss+(wind on ss+ll)+wind on pierbeam.
  • Load comb 104 dl+ll without if+bf+watercurrent+ff+wind on ss+(wind on ss+ll)+wind on pierbeam + wind on pier stem
  • Load comb 105 dl+seismic trans(dl)+0.2vll+0.5bf+ff+sf+water current.
  • Load comb 106 dl+seismic(longi) dl +watercurrent

Foundation
Pile Foundation with 4 Nos of 1200mm dia RCC Bored cast in situ Piles under each columns are proposed with Pile Cap at Top. The Founding Levels/Pile termination levels are fixed based on the required Pile capacity. In general Piles are terminated by socketing depth of 5dia of pile into disintegrated Rock or 0.5 dia into hard Rock.

Cement concrete pavement with 75 mm of uniform Thickness is proposed in M30 grade of Concrete. Deck is proposed with 2.5% camber in transverse direction to drain off the water with drainage spouts proposed at the edge of Kerb. Footpath with Hand rails is proposed on both side of bridge to facilitate pedestrian movements.

Encounters
The challenges faced are as follows:

  1. Analysis of Bow String Arch for 4-lane & footpath on either side, with 2 nos of Bow-Strings.
  2. The critical design of the foundation, as the bridge is proposed very close to old existing single lane steel girder bridge with pile foundation.

 

Fact File

Client: Tamil Nadu Highways-Trichy
Structural Consultant: Nagesh Consultants
Contractor: P.K.Mookanambalam & Co
Steel Tonnage:
a) Reinforcement Steel – 3200 MT
b) High Tensile Steel – 150 MT

Hager Electro (India) Pvt. Ltd, Pune

The client being German company by origin, was very clear about their requirements. In addition, to the production requirements they wanted to setup a revolutionary plant that would adhere to their philosophy of continual progress and superior quality. The brief mentioned the need for a green, maintenance free, sustainable building that adapted to the changing climatic conditions. Being Europeans, their work environment needed to have a mix of blue grey and white as they believe these are the colors of effective work environment.

Initial Thought
The initial thought to achieve the above brief steered the architects towards finding sustainable and energy efficient systems, which, can be automated to provide work environment that is AI (Artificial intelligence) controlled yet has a low carbon footprint. The need to create space, that was both aesthetically pleasing, and, maintenance free led us towards steel buildings technology and insulated panel walls.

Steel the necessity
There are three things that are integral towards making a project successful:

  • Cost of the material is significant in setting up any new project. Steel buildings are cost effective as they can create longer spans creating larger production spaces, they have good scrap value, they can be disassembled and reassembled easily, they are recyclable, and they are easy to transport.
  • Quality of production of steel is controlled by various norms and the fabrication (PEB- Pre-engineered buildings) are designed with various highly sophisticated software’s and are designed as per AISC and IS 800:2007. The whole production is mechanized thus giving us much more quality than a manually fabricated structure.
  • Time:The production of buildings is much faster as the whole process is mechanized. The erecting is also very fast as compared to RCC structures. Transportation is faster as the members are much lighter as compared to pre- cast RCC.Thus, steel was chosen to make the project cost effective, time bound,quality, conscious and sustainable.

Aesthetics
The building is provided with puff sandwich panels which make it look aesthetically appealing. These panels have been used for external cladding as a cavity wall. Glass facade has been used in elevation to capture more sunlight and to decrease the use of artificial light in building.The materials like ACP, Glass, are being used to create a Facade and fenestration that are not only aesthetic, but also contributes to saving energy.

 

The project was more so challenging as we had to convert a design which was frozen on a green field onto a campus of existing buildings, this meant removal of certain columns, strengthening of remaining columns, increase in height, modifying the roof structure to hang a walkable false ceiling. Improved aesthetic values internally and externally, choice of modern materials and latest technology towards walls, flooring, windows, ceiling, etc.and add a flavor of streamlined layout with a provision of green covers around the building to highlight the same. The Hager was a challenging project to achieve perfection in design performance, European standards as against existing brown field features. I am sure those who have seen the old structures and campus will have a shock and surprise when they see the newly designed and erected structure on the same piece of land without bringing down the old structure
Prashant Deshmukh
Principal Architect, Prashant Deshmukh & Associates

Sustainable Design Concept
Puff sandwich panels have been used for external cladding as a cavity wall which will reduce the temperature by 5 degree Celsius. It has a high load bearing capacity at a low weight. Puff sandwich panels are also used for false ceiling and was designed with the griple system. The false ceilings are walkable and enables good enough space to run services and utilities.

An evaporative cooling system has been used instead of HVAC. This system relies on adiabatic cooling. It saves electricity and operational cost is reduced, using the evaporative cooling system. Evaporative cooling system allows fresh air to circulate throughout a building and it forces hot air to displace out. Evaporation is a natural process and it does not require any refrigerant. It eliminates odour and state air out instead of recirculation.

Turbo vents provide year-round ventilation. These are low cost and high-efficiency vents which make them an extremely popular ventilation component. Roof vents and turbines must always be used with adequate soffit venting to meet minimum ventilation code requirements. It is needed to replace the turbine vent when it stops spinning because properly functioning turbine vents spin with the slightest wind.

Building management system has been used to control lighting/air conditioning/fire protection. Physical movement sensors are installed to save the energy. The use of right colors helps in reducing the heat penetration and help to be more sustainable. The false ceiling was designed to be walkable to cater the maintenance of all the utilities above the false ceilings.

Design Geometrics & Software used
The Germans strongly believed in squares and rectangles, not only for plans but also for elevation. The sandwich panels fascia is therefore, made to run across the periphery, hiding the roof profiles while achieving uniformity. The elevations are proportionately designed to suit the scale. The rectangular geometry is achieved through various façade elements including glass, ACP, and sandwich panels or powder coated aluminum louvers. The metallic grey framed design highlights the profile of the building with the strong language of squares and rectangles. A large curtain wall in the corner of the office building highlights the entrance automatically due to the scale and tint of the glass.

Software like AutoCAD was used for designing purpose, and software such as Stadprov8i, E-tabs were used for the structural detailing part of +the design of steel and RCC structures, MBS and Tekla for designing PEB structures; other than thatGoogle sketch up, 3-D Max, Lumion used for 3-D modeling and Photoshop and Microsoft Power Point used for presentations.

Experiences
Working with MNCs is always tough, as they are very aware of the requirements, quality standards and technological advancements. However, the architects loved the challenge of adapting new technologies to fulfill all the clients requirements by setting the bar for quality standards very high. The learning curve for the whole team was astounding. By the end of the project the whole team had becomehabitual to using and maintaining progressive techniques of communication, effective reporting, error free drawing delivery and predictive project monitoring.

The design took around a year for its completion. It commenced in Feb 2015, there were four revisions made in the design, The design got finalized in June 2015. The commencement of the work was in August 2015. The earlier completion date for civil works was given as May 2016, the total work was completed and handed over to the client in Oct 2016.