With the Supreme Court ordering the demolition of 32-storey twin towers in Noida, constructed by builder Supertech flouting rules, the challenge now is how to bring the towers down without damaging the buildings in the vicinity. This is the first time  such a tall building is being demolished in India.

Thirty-two floors of the towers, meant to go up to 40 floors, are ready and comprise 850 flats. The towers, according to the court order,  are to be demolished within three months. The expenses will be borne by the developer and they will also refund all those who had purchased flats in the towers with an annual interest rate of 12 %, the Supreme Court said. Besides this, Supertech has been ordered to pay Rs 2 crore to the Residents’ Welfare Association of 15 other towers.

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As UP Chief Minister Yogi Adityanath promised action against erring officials who gave required permissions for the illegal project, the experts are now considering how the towers will be brought down. This is the first of its kind and also the are is fairly congested.The closest building in the complex is separated by a narrow driveway, about 9 metres away from the twin towers. Another residential complex, ATS village is also adjoining the Supertech project. Ensuring there is no damage to adjoining structures will be a challenge.

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Demolition techniques

Implosion is the most commonly used technique. It involves using explosives to knock out a building’s vertical supports, causing the building to collapse onto itself from the inside out.

High-reach arm technique involves breaking the building top down. A demolition tool is attached to the end of the arm and is used to break up the building from the top down. 

Wrecking ball demolition, or crane and ball demolition, is one of the oldest and most common methods of building demolition and is typically used for small structures.

Selective demolition technique or strip-out is gaining popularity as it allows builders to reuse or recycle the building’s materials. Selective interior and exterior demolition of wood, brick, metals, and concrete allow for recycling and future use in new structures, blending the old with the new.

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Maradu demolition

The Maradu demolition is still fresh on many minds. In 2020, four towers of an apartment complex — housing 343 apartments, were demolished in Kerala’s maradu for flouting environmental norms. There were buildings in the adjoining areas but none on the complex. The nationally-televised demolition went off smoothly with no damage to other structures

Demolition technique used

The Maradu flats were demolished using the implosion technique. A total of 960 holes were drilled in primary vertical supports and 15 kg explosives were plated in them. When detonated, the buildings collapse ito itself and the debris spread to the front yard and the backyard