A team from IIT Roorkee has sought a sample of the underground soil in Bowbazar from the Kolkata Metro Rail Corporation (KMRC), the implementing agency of East-West Metro, to understand the reasons for the May 11 subsidence, officials said.
“The team from IIT Roorkee has sought a sample of underground soil and documents related to soil tests carried out in Bowbazar and the structures that have been built underground. They will analyse and come up with suggestions,” said N.C. Karmali, director (projects), KMRC.
“Primarily, the team will analyse and study the soil and all documents related to soil tests.”
Narendra Samadhiya and Akanksha Tyagi from IIT Roorkee had visited the subsidence-hit zone in Bowbazar on Sunday to assess the aftermath of the disaster that has forced the KMRC to suspend Metro activities in the Bowbazar area till the end of the monsoon.
The KMRC has engaged IIT Roorkee to identify the reasons for the subsidence.
An excavation of soil to grout a “blind spot” under the Howrah-bound tunnel of East-West Metro, which once fully functional will stretch 16.5km and connect Sector V with Howrah Maidan, had led to leakage of underground water on the night of May 11.
The leakage was followed by subsidence and cracks in at least nine buildings in Bowbazar’s Durga Pituri Lane. More than 160 people have been displaced.
“On Monday, the team members met senior officials for a preliminary discussion to review the measures that have been taken and discuss further technical measures,” said a senior KMRC official.
After going through the reports of soil tests, the IIT team will come up with short-term and long-term measures that the KMRC will have to implement before resuming Metro work in Bowbazar.
“The team will possibly come up with a model for tunnelling work around Bowbazar in an attempt to prevent further disasters,” the KMRC official said.
A team of experts from the Jadavpur University has already submitted a preliminary report identifying nine buildings as “severely damaged”.