Construction work of the underground East-West Metro tunnelling system at the heavily congested Bowbazar area of central Kolkata, which led to the fresh appearance of cracks in at least 10 residential buildings on Wednesday evening, resulted in a familiar picture of panicked residents leaving homes with bare essentials on Thursday and Friday for temporary shelter in neighbourhood hotels.
The Kolkata Metro Railway has been asked to test the soil condition in Bowbazar to decide the fate of the buildings that have developed major cracks, mayor Firhad Hakim said on Friday.
The reason for the new cracks in the houses of the Bowbazar area is the water level, say experts. There are multiple water levels in parts of the locality. At the moment, the tunnel is 31.8 metres below the ground. There is a tunnel 25 metres below the ground. The diameter of this tunnel is 6.8 metres. The water is gradually rising from below this.
It is known that there is an aquifer in the area. The two sides of the tunnel should be connected. About nine metres should be added. It will be paired with a concrete box joint, which is in the old Metro. And the problem started with the process of joining this box. That is because the lower part of the tunnel or the land or platform needs to be concreted. While going to work on that concrete, about 5 metres of digging was done. And from there the water has started to flow continuously. Grouting is now being carried out to stop this water.
Grouting is the process of injecting a combination of chemicals, cement, and water to fill a void. For this water to enter, vibrations have been generated. Engineers believe that due to this, cracks appeared in several houses in Bowbazar, particularly in Durga Pituri Lane.
For residents, it’s like a horrifying replay of recent past. In 2019, cracks were found in several houses during the construction of the East-West Metro tunnel through Bowbazar. Cases were reported again in 2020. Both times, many families had to leave their homes and move elsewhere. Some of them have not been able to return. So this time, the locals are reluctant to leave.
Visiting the spot, local councillor Biswarup Dey spoke to the residents. MLA Nayana Bandyopadhyay also went to the locality.
According to Metro sources, the work of making a tunnel in that part is over. At present concrete-pouring is going on in the tunnel. Besides, two tunnel boring machines named ‘Urvi’ and ‘Chandi’ have been lifted from the underground. Ground concreting is currently underway to complete the tunnel.
“We have come down to the streets in fear of death. But where will we go? Those who had left before have not been able to return yet,” said one of the residents.
Authorities say families are being moved out as a precautionary measure.
“Residents have been evacuated,” said NC Karmali, project director at Kolkata Metro Rail Corporation, who is in charge of the East-West Metro. “They will be taken to a hotel as a precautionary measure. There are 14 families. All that is to be done on our behalf is being done. The situation is under control…The cracks had just started. There is nothing to worry about.”
Read all the Latest News , Breaking News and IPL 2022 Live Updates here.