Can you tell us something about the project in terms of its magnitude?
Yes, first of all I would acknowledge the vision of the Mumbai Metropolitan Regional Development Authority (MMRDA) for planning such a Big & International level convention center in Mumbai and then comes Reliance Industries, the clients, who appointed us for taking up this challenge to design such a very large & complex project and then all other stake holders, architects, consultants and contractors who did a fantastic job.
As far as its scale is concerned, it is an 8 million sq. ft construction area in one single building. One can imagine this convention centre where we are sitting now is 1.3 million sq. ft, whereas 8 million sq. ft is so many times of this space that we are talking of, and the challenge here was of course the time period within which we had to complete the project. We were given only 5 years from design inception to the completion and that challenge was taken by Reliance and we were all involved in it.
What was your overall role in the project?
My company is purely into structural design services. There must be more than 40- 45 consultants involved in this project & more than 100 vendors and contractors.
So, my place if you look at the huge project organization, is somewhere in the matrix of vendors and consultants, but of course, it’s a key role- structural design is the basis of the entire project. Responsibility of making the project safe & stable lies with the structural engineer.
What was the initial thought process before finalizing the design of this project?
The architectural design of course was done by TVS Design, who specialize in Convention Centers from Atlanta, USA. When they showed us the initial architectural planning, we were quite excited, because there were huge column-less spaces & then the respective floors and above these spaces they had planted the commercial & residential spaces & those columns naturally could not come down in the convention & exhibition spaces.
We immediately realized that there were challenges in terms of structural framing & there had to be large scale transfers – load transfers & column transfers over large spans so that the exhibition center as well as the banquet hall could remain column free. Hence, this was a major challenge right in the beginning we had to face.
What are the key structural elements of this project?
There are 5 basements in this project and therefore the excavation went down 21meters deep from road level. As this plot lies next to the notorious Mithi river in Mumbai which is prone to flooding and toxic water getting collected, the exhibition center had to be designed keeping this in mind. The exhibition space was designed for very heavy load of five tons per sq. meter so that any kind of exhibition could be held there and in fact five tons per sq. meter can support exhibitions of ships & Jumbo jets.
The exhibition center had to be a large column free structure and above that were banquet halls which are column free spaces as well, with a span of 70 meters. On top of the banquet hall is a garden as the podium top forms sort of ground for the residences which are planned on top of the podium. Almost 1.8 meter thick soil load had to be supported on this banquet hall roofs. Naturally these large span structures had to be conceived in structural steel. Steel was the obvious choice for the convention center but the residences which were planned above the podium had to be built in conventional material because in India people don’t like to see steel beams hanging in the ceiling. So residences had to be in concrete and this was another challenge supporting heavier construction material over a structural steel frame. There is a theater with 2500 audience seating capacity. The roof is spanning 40 meters as the auditorium cannot have columns inside. On top of the roof of the theater there is a clubhouse & swimming pool.. So, in-short heavy loads are supported on very long span roof structures in all blocks of the building.
What were the various challenges faced by you in making of the project?
Since the construction had to be completed in 5 years there were almost 14 or 17 tower cranes dotted all over the plot & construction was happening everywhere. The construction methodology of each of the blocks – theater, exhibition, retail and the office was different. It was like working on 10 projects simultaneously. The methodology of the same was devised by the contractor, with our suggestions and modifications, to ensure smooth working. As 10 different sub-projects were going on simultaneously it required identification of the requirements of each of the projects and separate teams were put to work on them.
The analytical model of the building had to be one unique model and the member forces were extracted from the same model and then used by different teams. The strategy that we adopted right in the beginning was that we recognized that we are not only the structural designers but we are part of the larger team & whatever we do, whatever output we take out from our models, our software models should go as input to the next user and so that there is no duplication of work. The inter-operability of software’s was used in the project right from the beginning.
What role did steel play in the making the world-class convention and exhibition venue in Mumbai?
There is no doubt that there was no material that we could use for such large spans & heavy loads other than steel in this building. You can imagine that the exhibition center is 225 meters long and 90 meter wide & the banquet halls are 150 meter by 70-meters in dimensions. Then the theater having 40 meters span, so all these loads could be supported by no other material than steel.
In fact we derived a very beautiful benefit from using steel in the roof above the banquet hall which is spanning 70 meters. We designed a 2 floor deep, 9 meters deep truss and that truss had a middle level as well as a floor. The bottom cord formed one parking level, and the middle level was also a parking floor itself. The top cord was used to support the gardens. This is possible only because we used steel trusses which allowed cars to pass through the truss’s diagonals & verticals.
As the planners were falling short of cark parking in the basement, the cars could be housed in these trusses. Thus it was optimization of space as well as material, which was possible only because of steel. When you use steel, you can fabricate it while you’re doing something else. While the basement was been constructed, almost 50 per cent of the steel fabrication was complete. This was a big contribution to our efforts of achieving the targets on time.
How did the software RAM and RCDC aid in the construction of DAICEC?
RCDC is truly speaking a concrete design software. We modelled the building using RAM, STAAD.pro and analyzed it for the various forces – dead loads, live loads, earthquake loads, wind loads. We got the member forces. The forces in the concrete members were transported to RCDC which in turn gave us the reinforcement design of the concrete members.
RAM & STAAD.pro softwares have been used by us for the last 30 years and they are time tested & completely polished, they can give us all sorts of analysis data. It was seamless and STADD output can be transported to Tekla quite easily.
What are the unique features of Dhirubhai Ambani Convention Centre?
I believe that it’s the largest in India. There is no such huge space which is dedicated to Exhibition & Convention Center. Apart from Goregaon which is a huge ground so far, but this is first of its kind in India – Modern Convention Center with facilities.
Although it took so long, Mumbai today has this Cultural & Exhibition Center with all the facilities – the Exhibition Hall, Banquet Halls, Meeting Halls, Conference Rooms, Theaters, World Class Theater of 2500 capacity and then Art Gallery, Cultural Plaza, Auditoriums, Residential Blocks & some of these residences are also going to be serviced apartments for guests who would be coming for the conferences. It’s a complete whole infrastructure.
What were the project timelines from design to execution and how were they met?
The construction started in January 2014. The structure was completed in 2017 march which is 39 months, but the high point is structural steel fabrication. Almost 30000-32000 metric ton of steel was fabricated in just one year that was the high point. Just the next year a huge quantity of steel was in place, erected – which was a great achievement.
Can you share details about project collaboration between various parties involved?
As mentioned earlier, various contractors, vendors did use output provided by us and that’s how the duplication of work & time was avoided. Of-course we had so many glitches as it was like working on 10 different projects going on simultaneously, and the interfaces of those various areas, the speed at which we were working and then we were having RAM & STADD, Revit, ETABS, Auto CAD & so many software’s going on together & the Tekla person waiting for inputs, so all these things definitely had its ups & downs but the software teams were helpful & whenever problem cropped up, they smoothened the situation quickly.
How was your experience and what are your learnings working on the project?
The key learning is that as a structural engineer we plan our work in advance along with the strategies that are not only useful for structural design, but also for the overall project completion. Just reiterating, this project was like working on 10 different projects. So we planned our resources, manpower & the design strategies, structural design strategies that helped other disciplines as well.
The learning is-along with doing this kind of planning in structural design, we can also plan strategically to make effective use of software. Bentley calls them playbooks – RCDC is a playbook, RAM is a playbook and so on. So these playbooks have to be seamlessly integrated one after the other, so that you can have this group of softwares playing consolidated role avoiding wastage of time and duplication of work. Ensure interoperability between the software has to be planned just as you plan your structural design activities. That is the key to achieve timely & quality construction.