Heavy steel used in construction delays Chandni chowk bridge demolition
Finally, after more than a month of pre-demolition work, the old bridge at Chandni chowk was demolished at 1 am on October 2 by the National Highways Authority of India (NHAI) through the private agency ‘Edifice Engineering’, which carried out the blast through the ‘controlled blasting’ method
Finally, after more than a month of pre-demolition work, the old bridge at Chandni chowk was demolished at 1 am on October 2 by the National Highways Authority of India (NHAI) through the private agency ‘Edifice Engineering’, which carried out the blast through the ‘controlled blasting’ method. Edifice Engineering is the same company that demolished Noida’s Supertech Twin Towers in the last week of August this year, officials said.
Whereas, even after the blast, the bridge – built in 1992 by the then state public works department (PWD) - did not fall down immediately as the amount of steel used inside the pillars was more than what was anticipated by the NHAI team. Later on, with the help of pocklain machines, the remaining part of the bridge was broken down and finally, after an hour, it all came crashing down.
Anand Sharma, chief engineer, Edifice Engineering, said, “The controlled blast method was used for the blasting of the 30 metre-long bridge. The blast was successful and all the parts into which the explosives had been drilled blew up. But we suspect that some of the drilled holes might not have taken the blast from the NDA road side. Even the middle pillar of the bridge was blasted but it did not fall down immediately and for that, we had to use pocklain machines to break it down. The amount of steel was more than we had estimated due to which, it could not be demolished at one stroke but the blast was successful.”
“For bigger structures like big buildings, there are explosive techniques used to demolish but this was a small structure so we had to use the controlled blasting method. These are low intensity blasts wherein the concrete is removed from the steel structures. There was no need for a second blast. We are carrying out a detailed audit of the blasting as to which holes did not blast and what were the reasons behind the same,” Sharma said.
Chirag Chheda, co-owner, Edifice Engineering, said, “The bridge was demolished at 1 am on Sunday through a controlled blast and everything was executed as per plan. Now, we have pressed earthmover machines, forknails, and trucks into service to clear the debris from the spot.”
Following the demolition, several earthmover machines and trucks were pressed into action to bring down the hanging structures and lift away the debris. The work of clearing the debris from the highway went on till the morning and at around 10.30 am, one side of the highway was opened to vehicles coming from Mumbai headed towards Katraj and within the next half-an-hour, another side of the bypass highway was opened to vehicular traffic.
Pune district collector Dr Rajesh Deshmukh said, “Certainly, the bridge demolition work, right from the pre-demolition work to the actual blast at 1 am on October 2 was carried out smoothly. The blast was successful, but the only thing was that some explosives in the holes did not blast and the steel used during construction of this bridge was heavy steel. So, it took time to completely demolish, but as all systems were in place, the work to demolish the remaining part of the bridge was carried out immediately after which the work of removing the debris started at night with everything cleared from the highway till 10 am.”