Supertech Twin Towers Demolition: Structures to crumble in 12-13 seconds

The authority said that fire tender, ambulance etc will be parked on the road near the park facing the twin towers.

Demolition of the Supertech’s Noida Twin Towers on August 28, being executed using the controlled implosion technique for which more than 3,700 kg of explosives will be used, is expected to generate more than 30,000 tonnes of waste.

After all the explosives have gone into the holes, experts will start connecting them floor wise and eventually, building-to-building connections will be completed following which the final button will be pressed.

"Explosion is one thing and there is something that detonates it. It has to charge it. From a safety perspective, the final connection will be established on the last day. The final connection will be established only at 2 pm when a wire and a shock tube will come out from one point of the building to the point where we are going to press the button," Edifice Engineering partner Uttkarsh Mehta told Moneycontrol.

A six-member team stationed 250 mteres from the twin towers will press the final button. The explosives will take exactly 9 seconds to ignite and another four to six seconds for the structure to crumble.

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“The entire process will not last more than 12 to 13 seconds,” he said.

The sound will be like a thunderclap.

“On the day of the test blast, the sound resembled crackers. That’s when we had blasted six columns. During the final blast, the number of columns is humongous, and the sound will be akin to that of lightning before it rains. The volume of the blast will be close to 150-200 decibels,” he said.

The twin towers are being demolished following a Supreme Court order that found the structures to be illegal and built in violation of norms. According to the estimates prepared by the project officials, the demolition of the Apex (32 storeys) and Ceyane (29 storeys) would leave behind approximately 30,000 cubic metres of debris to be cleared and clouds of dust to dissipate.

Debris management planning is already on and Edifice Engineering has submitted one level of report.

While the buildings will be demolished in a few seconds, it may take at least three months to remove all the accumulated debris, said Mehta.

“However, we are still in the process of finalising the land where these debris will be disposed of. Much of the debris we will be processing within the site itself. Small lumps of clear debris will be segregated on site and there will be no steel in the debris. Only pure pieces of cement concrete will go to the landfill site. We are in talks with Noida Authority. They have assessed the land, the quantum, the depth of the land, and we should be able to finalise the plan soon,” he said.

“We will be clearing those two basements and some amount of debris will go into the basement as we cannot leave it as a pit. It has to be covered. Some level of debris will go into it, and we have guesstimated that 30,000 tonnes of debris will be disposed to those landfill sites by trucks.”

After the blast, debris will be disposed of in line with the Construction and Demolition. Waste Management Rules, 2016.

Dust cloud- a major challenge

Pollution control measures are also in place for controlling the dust cloud that will take 5-10 minutes to settle depending on the wind speed. Dust and noise levels in the area are being monitored on a daily basis, he said.

The biggest challenge of the demolition will be in containing the dust cloud. Mehta said that his team has been tracking the flow of the wind for the last one week or so and they have found it flowing towards the West. If the same pattern continues, then most of the dust would blow towards the front side of the twin towers, which is a road followed by an open city park, he said.

The favourable wind direction would prevent the dust from settling within the premises of Emerald Court and ATS Village societies both in close proximity to the twin towers.

The implosion method is the fastest, cheapest and the safest way to demolish a building. The only negative thing is the dust. There is no means with which this can be controlled. This is instantaneous, so much so that even if you have 10 fire tenders you cannot control it, the towers will come down in seconds and in milliseconds this dust is going to be generated and in 5-10 minutes it will get dissipated as well depending on the wind speed direction, he said.

“If it rains we can control 2-3 percent of this dust cloud. Our technical experts have said that the dust that will be generated actually acts as calcium. Cement dust is like calcium and can be used as a fertiliser. Calcium is good for trees,” he added.

Know More: Noida Twin Tower Demolition: The Man Who Will Bring Down 32 Floors