Around 20 hi-tech seismographs and 10 black boxes -- an electronic device to record sound in aircraft -- were among the equipment placed inside the Supertech twin towers during their demolition, a senior CBRI scientist said.
Besides these, drones with thermal image cameras were also deployed outside the towers to capture pictures and videos that would help in future research, the Central Building Research Institute (CBRI) scientist said.
The CBRI was appointed by the Supreme Court as a technical expert for the demolition of Supertech's nearly 100-metre-tall illegal structures in Noida's Sector 93A.
It was the CBRI that selected Mumbai-based Edifice Engineering that safely brought down the structures by 'waterfall implosion' in an eye-popping event that caused no structural damage to nearby buildings as close as nine metres.
The CBRI had roped in the Central Institute of Mining and Fuel Research (CIMFR) for ground vibrations. Its teams from Dhanbad in Jharkhand and Bilaspur in Chhattisgarh were present during the demolition.
"We had 19 seismographs. These are high-end and highly technical seismographs which were installed in a 150-metre range from the twin towers. Some equipment were placed in the basements of the twin towers while others were placed on different floors so that we could get the magnitude of the vibration magnitude of the two buildings," CBRI's senior principal scientist Dr Debi Prasanna Kanungo told PTI.
"We had also placed 10 black boxes - five in each tower. This was CBRI's idea. We also used drones and thermal imaging cameras, which will help us get pictures that can be processed for further research studies," he said.
"All the information gathered from these equipment and instruments will help us in future for material studies, demolition and construction-related research. We also used instruments like geophones to record and study the movement of vibrations within buildings and also give an idea about the load a building could during such activities besides devices to study soil conditions," Kanungo said.
The thermal imaging cameras form images using infrared radiations and are largely used in fires and other disaster management activities to detect people engulfed in thick smoke and dust.
The CBRI has signed a research collaboration and non-disclosure agreement with Jet Demolitions and Edifice Engineering wherein both groups will share their data with each other for study and research purposes in the field.
Kanungo, who led the twin tower demolition monitoring team, said that several high-technology equipment and instruments were placed inside the twin towers and their findings will be very useful for future studies.
"There has been no structural damage in the nearby residential towers of ATS Village and Emerald Court societies. Besides a compound wall of ATS Village, some window panes have broken. We had asked for a post-demolition structural audit which is to be done by Supertech. Once that is done, its findings will help us analyse the demolition," he said.
On the ground vibration report during demolition, the CBRI official said, "It will take time. Recordings have been done by our devices and also those placed by them (Edifice and Jet Demolitions). Once that will be analysed, it will help us in future research related to ground vibrations, building constructions, etc."
The Noida twin towers are the tallest illegal structures to have been demolished by implosion technique in India yet. Prior to this, four residential complexes of 18-20 storeys in Maradu municipal area of Kochi, Kerala, were razed in a matter of few seconds by implosion in 2020.
Both demolitions had come in compliance with the orders of the Supreme Court, which held that the structures were built in violation of building norms.
