The Kolkata Metro Rail Corporation (KMRC), the implementing agency of East-West Metro, has started fixing steel props to avoid further deterioration of the crack-ridden buildings in Bowbazar’s Madan Dutta Lane, officials of the agency said.
The agency is also grouting their foundation to avoid further tilt because of subsidence.
However, several engineers involved in the Metro tunneling work, including in the East-West Metro project, have said such protections should have been taken before starting the construction of “cross passages” to link the two tunnels.
On Monday, pumps with long hose pipes were set up in the narrow lane to pump in concrete mix under the foundations of some of the houses where cracks appeared on Friday morning because of subsidence triggered by Metro work.
Senior officials said the concrete mix that was being used to grout the foundation would fill gaps beneath the structures and prevent underground soil from shifting further. This will ensure the buildings don’t develop any more cracks.
“We want to repair some of the buildings in Madan Dutta Lane where minor cracks have appeared and ensure the residents return home at the earliest,” said N.C. Karmali, director, projects, KMRC.
“A team of consultants has already assessed the condition of the affected buildings. After repairs, we plan to invite them to revisit the buildings and identify those where residents can return.”
However, some of the experts pointed out that if the props had been fixed and residents evacuated as precautionary measures before the construction of cross passages had begun, the disaster could have been prevented or its scale minimised.
“Since two similar disasters had taken place in the area since 2019, the authorities should have taken additional precautions. They should have fixed props for the old buildings before starting work on cross passages,” said an engineer involved in the project on another stretch.
A team of experts from Stup, a consulting agency, has assessed over 10 buildings where cracks appeared on Friday, said a KMRC official. “There was no deliberate delay after the cave-in.”
The KMRC has said it would pay Rs 5 lakh each to the house owners who cannot return home within 30 days from Friday. The affected shop owners whose establishments measure less than 100sq ft will receive Rs 1.5 lakh as compensation. The ones with establishments measuring above 100sq ft are entitled to Rs 5 lakh as compensation.
“Work inside the Metro tunnel cannot be put on hold for long. We want to start it as soon as the shifting of loose soil stops and the area has completely stabilised,” said a KMRC official.