India is home to one of the most remarkable landmarks in the world! Located near the banks of Sabarmati River, the Narendra Modi Stadium in Ahmedabad, Gujarat, is the world?? largest cricket stadium and the second-largest stadium overall. First constructed in 1982, it had a seating capacity of about 35,000 spectators. The stadium can now accommodate over 110,000 cricket fans, surpassing the Melbourne Cricket Ground, which has the capacity to accommodate 100,000 spectators.

Initial brief

??&T?? brief was to construct a new stadium on the footprint of the older stadium with three times more capacity,??shares MV Satish, Whole Time Director & Senior Executive Vice-President – Buildings, L&T Construction. ??he facility also had to feature four dressing rooms, a clubhouse with 50 deluxe rooms and five suites, six indoor pitches, two outdoor practice grounds with pavilions and a main ground lit entirely with LED lights.??The mandate for this design-and-build tender from the client, the Gujarat Cricket Association, was awarded in 2016 and the project was completed in time for the ??amaste Trump??event in February 2020.

Overcoming design challenges

??ize and scale were the biggest challenges,??says Satish. ??he task of constructing an elliptical or oval-shaped stadium began with the detailed design for architecture, structure and allied services developed by the company?? in-house team of designers and engineers?? Myriad challenges were faced during project execution:

• To speed up construction, precast technology was adopted. The entire superstructure of the stadium is made up of huge, unequally shaped ????columns (30 m in height, 2.7 m in width) weighing some 285 tonne. These were all precast as one piece and transported and erected at an extremely logistically challenged project site.

• Prestressed cables and PTFE fabric were used for the steel roof structure. The roof has 1,000 m perimeter length, 10.5 m height truss and 30 m cantilever, and is provided at an elevation of about 40 m from ground level. The fabric design and execution teams had to interface for perfect execution.

• The site is located 3.9 km from the runway of Ahmedabad airport. The permissible height for structures within a 4 km radius was only 45 m whereas the stadium rose to 51 m. The matter had to be taken up with the Airports Authority of India (AAI) to get the design approved without changes.

• The site had obstructions on three sides with 1.3 km of the total 2.7 km boundary conflicting with an abutting residential colony, while there was a high-tension 132 kV wire that stalled 25 per cent of the construction on the other side, until it was shut off by the Gujarat Energy Transmission Corporation (GETCO).

Special features

To give spectators a 360? unobstructed view of the field of play and the boundary line from any given location on the podium required much detailing and precision in space planning and engineering. The appointed architects, Populous, developed an innovative design to accomplish this. ??s you climb to the upper seating bowl, you experience a panoramic view of the field of play, gradually offering a vista experience,??informs Satish.

The stadium has many interesting features:

• Each aspect of the stadium, like ease of entry and seamless movement of 1,10,000 spectators, positioning of each tier and placement of the pillars, has been meticulously planned.

• The 30 m cantilevered roof gives the stadium an impressive and aesthetic look that has been designed on a spoked wheel concept, comprising a steel truss outer compression ring and radial and circumferential cables with a fabric cover.

• It is the first Indian stadium to have as many as 11 different pitches with the same soil used for both the playing and practice pitches.

• It is the first stadium with four sets of dressing rooms for the players, each with an in-built gymnasium and other facilities.

• It is the first stadium in India with LED lights that are uniquely designed and placed in clusters to eliminate shadows of players on the ground.

• The stadium?? state-of-the-art drainage system can remove rainwater within 30 minutes of the rain stopping.

The stadium has the distinction of being the only cricket stadium in the country to be awarded the Gold Green Building rating by the Indian Green Building Council (IGBC). The award recognises the various green features of the stadium, like the 100 per cent LED lighting to reduce energy consumption, rainwater harvesting capacity of 3.2 million litre per day, potable water saving of 1.2 million litre every year and onsite sewage treatment plant of 1 mld capacity to treat and reuse 100 per cent wastewater for landscaping and flushing requirements.

Machinery and materials used

??ithout equipment, lifting tools and tackles, precast and structural erection was a dream!??says Satish. Some major equipment used included self-propelled modular trailers, crawler cranes in various sizes and 52 hydraulic jacks to lift the cable net structure for the roof (all at a time).

Specially designed self- compacted concrete (SSC) was used to avoid the use of vibrators and to assure quality. A special type of cable net was used on the roof that did not have any mechanical cantilever structure; the PTFE fabric was placed in a 30 m cantilever.

Safety measures

At peak time, L&T had almost 4,500 workmen onsite in addition to over 150 engineers, designers and architects. To ensure the safety of workmen and employees while working at heights and in precariously positioned spaces and safe crane movement along the high-tension line, the following measures were taken:

• A safety height simulation with BIM 360 modelling was developed to monitor and control the height at which work was happening at the upper bowl.

• Fall protection at a height of 30 m with CCTV monitoring was installed.

• Fire load calculations were done at all facilities with independent assessment and fire-fighting equipment installed as per the fire load.

• The entire site was monitored using CCTV cameras and the footage helped the team to monitor safety measures by zooming into certain sections to check safety railings, safety nets on the staging and other aspects.

How technology helped with the construction challenge!

The elliptical or oval shape of the stadium posed certain engineering challenges as the precast erection had two radii. Coordination of the MEP (mechanical, electrical and plumbing) works with the civil and structural works was a huge task to address. The team used building information modelling (BIM) software, SYNCRO, to execute this successfully.

– PRAHARSHI SAXENA