The demolition of the Noida Supertech twin towers on August 28 was a marvelous engineering feat that took months of preparation for the immaculate execution of the project. The biggest challenge faced by the engineers while demolishing the giant towers Apex (32 floors, 103 meters) and Cyane (29 floors, 97 meters) was to carry out the demolition with minimal or no damage to the adjacent buildings barely 9 meters away. Moreover, they had to ensure the safety of the 5,000 inhabitants of these neighboring buildings. Engineers responsible for executing the demolition project deployed the waterfall technique to achieve the goals of safe demolition with deft precision. Since the Supreme Court’s mandate was to complete the project in the shortest time without harming the neighboring properties and lives, a waterfall implosion was the best option from the cost angle.
Supertech Twin Towers – The Specialty of the Demolition Technique
The term waterfall technique or implosion has gone viral courtesy of the extensive media coverage received by the demolition project and escalated manifold across social media. But what is the technique all about? The name of the precision demolition technique bears enough hints about the demolition process. The technology behind the demolition process must ensure that the structure crumbles like a house of cards and the debris falls in a cascade resembling a waterfall’s water column without spreading far. While implosion helps to control debris falling within a small arc, an explosion would fling the debris far and wide. Therefore, demolishing any large structure in an urban setting with other structures nearby involves the process of implosion.
Ensuring the Safety of the Residents
The process of precision demolition involved a series of controlled explosions in turning the structures into a massive mass of 55,000 tonnes of debris in a few seconds. But it was vital to prevent damage to the neighboring buildings standing dangerously close to the twin towers. The authorities had arranged for the evacuation of the adjoining areas’ residents before starting the demolition process to ensure their safety.
What is Implosion?
In relation to structural demolition, the term implosion means that despite using explosions (dynamites) to break the structure, the debris would fall within the precincts of the premises. Having demolished four high rises in Kochi in 2020, the company tasked with the project has good experience using the waterfall technique for building demolition in urban areas. The technique relies on the principles of gravity to carry out the demolition in a well-calculated manner. The process starts by removing the base of the structures in such a way that shifts the structure’s center of gravity by a few millimeters. Consequently, the structure crumbles systematically while the debris falls almost perpendicularly in a pre-determined manner.
For carrying out the implosion of the Supertech Twin Towers, the engineers had to pack 3,700 kg of explosives across various floors of the structures like bands. They had to drill 9,640 holes, each measuring 2.634 millimeters accurately to the last digit.
The project has been highly successful, with no reports of significant damage to the adjacent structures.