| Artist’s impression of South City, on Prince Anwar Shah Road: Overdrive for safety and stability
Procuring advanced software platforms to assess dynamic response of the superstructure and assaying how the towers will behave under extreme wind velocity and seismic disturbances. Finding the right ratio between mass and stiffness and ensuring the right balance between super-structure and sub-structure. Incorporating the latest in earthquake engineering to minimise damage and ensure the buildings don’t collapse in a heap if Bhuj is revisited here…
With highrises getting taller by the year and the city bracing for a very vertical skyline in the new areas of growth, developers have gone on overdrive to extend the comfort zone to the topmost floors, benchmarking themselves to latest international standards in structural designing and engineering.
From Hiland Park, which recently inaugurated its first phase, to Silver Spring on the Bypass, where construction is on in full swing, to South City on Prince Anwar Shah Road, which promises to “rewrite the rules of urban development in Calcutta”, high-profile highrises are aiming high and digging deep.
South City, for instance, has conducted extensive geo-technical investigation and soil test up to a depth of 50 metres and executed the static-cone penetration test to assess the overall load-bearing capacity of the soil. “This will ensure that the foundation and the super-structure will be structurally safe and stable,” says one of the directors.
The Rs 300-crore integrated mixed-use project has appointed Meinhardt (Singapore) Pte Ltd, internationally-renowned structural consultants, to ensure this “safety and stability”. Meinhardt has carried out an extensive study on the structural and foundation design of the buildings with the ETAB software, used for designing high-rise towers around the world.
Engineers of the Singapore firm have also conducted 3-D analysis of the design to assess the lateral load and the static and dynamic stress on the structural elements of the towers. “We are trying to virtually eliminate any settlement. While the Indian code permits settlement up to 75 mm, we are aiming at a maximum settlement of 20 mm only to ensure greater comfort for the residents,” says Predrag Eror of Meinhardt.
A spokesperson for M.N. Consultants, structural engineers for Hiland Park, observes: “The two most important aspects of designing towers are formulation of efficient lateral load (seismic and wind) resisting system and an efficient foundation system to combat the soft soil of Calcutta (which has high settlement potential).”
The frame-shear wall structural system at Hiland Park was adopted to resist seismic and wind forces. All possible loads, like gravity loads and lateral loads, were assessed and analysed with special emphasis on seismic loads, the engineers maintain. Dynamic analysis using the response spectra method was performed to assess the “exact behaviour of the structure during an earthquake”.
The foundation and super-structure of the Silver Spring towers have also been designed “with due consideration for earthquake factor and wind load”, says architect J.P. Agrawal. “Shear walls are used instead of the conventional column system to provide better internal layout and better stability,” he says. The Bypass project's structural design was cleared by International Structural Consultants, involved in the structural design of Petronas Towers.