A for tnight has passed since cracks appeared in buildings in Bowbazar following a subsidence triggered by East-West Metro tunneling work, but a roadmap to resume work is yet to be ready.
A team from the Delhi Metro Rail Corporation (DMRC) is awaited soon, said officials of the Kolkata Metro Rail Corporation (KMRC), the implementing agency of East-West Metro, which will connect Sector V and Howrah once fully operational. Currently, trains on the corridor run between Sector V and Sealdah.
The visit by the DMRC team was delayed by a few days because of Diwali, said sources in the KMRC.
ITD-ITD Cementation, the contractor that is building the twin tunnels of the Metro on the Esplanade-Sealdah stretch, is consulting international experts, too. A team from a Singapore-based consultancy recently visited the site.
But no one seems to know when work will resume.
“The DMRC team should be here soon. They will inspect the tunnel and suggest remedial action. If need be, they will hire external experts. We are waiting for their feedback before resuming work in the critical sections,” said C.N. Jha, managing director of the KMRC.
Cracks appeared in around a dozen houses in the Bowbazar area following water seepage during construction of a passage to connect the two tunnels of East-West Metro on October 14. The seepage of water has been arrested but the construction of the passage is on hold.
The two tunnels of East-West Metro are to be linked by eight passages between Sealdah and Esplanade. Three of them are complete and construction of the fourth led to the accident.
The October 14 subsidence and the resultant cracks in the buildings was the third such disaster caused by Metro tunneling work since August 2019. Hundreds of residents and traders have been displaced from their homes and businesses.
“It is still too early to say when work will resume. We don’t want a repeat of the tragedy. The damaged portion has since been secured but there could be more such vulnerable areas,” said an official of the KMRC.
After the latest accident, The Telegraph spoke to multiple engineers and international experts about the possible way out. Some engineers, including two who had been associated with the project, suggested injecting liquid nitrogen into the ground to freeze the underground water or increasing air pressure inside the tunnels to prevent seepage of water.
ITD-ITD Cementation got a team from a Singapore-based construction and engineering company to inspect the Bowbazar site last week.
“The team was here between October 20 and 22. They inspected the tunnel and asked for some readings, which we have supplied. We are waiting to hear from them,” said an official of ITD-ITD Cementation.
