The Kolkata Metro Rail Corporation Limited (KMRCL), the implementing agency of the East-West Corridor at Bowbazar is carrying out the installation works of steel liners inside the east-bound tunnel at Bowbazar.
A stretch of the two tunnels near the cave-in zone had been affected due to the mishaps at Bowbazar. Following one of the incidents of subsidence, there was a slight disturbance in the shape of the tunnels, both east-bound and west-bound. The implementing agency measured the stretch that was affected due to the subsidence and designed steel liners to rectify and repair the inner walls of the tunnel.
“We have designed the liners in a way that there is no default further,” informed an official source. “Although the designers told us that those were safe, we wanted to have additional precautions,” said the official.
As pointed out by the official, the implementing agency is simultaneously doing grouting works to strengthen the structure. “We are installing steel liners and doing grouting from behind. In the east-bound tunnel, most of the works are complete,” informed the official. In the east-bound tunnel, the KMRCL is said to have done half the work on installation of liners. The remaining works would be carried out simultaneously when the trains would be operational on the two legs of the East-West Metro. As elaborated by the official, the works would be temporarily suspended on the day when the commercial train operations would not be run for movement and detailed inspection of the rakes. “The west-bound tunnel would be operational 24×7, 365 days,” added the official.
According to the source, work is remaining only on a patch of about 200-250 meters. In the rest of the stretch, the tracks have been laid by the implementing agency. “We are going slowly and steadily with the work so that there is no further mishap,” added the official.