Kolkata Metro Rail Corporation no to E-W shaft shift from Wellington – Times of India

Kolkata News
KOLKATA: The KMRC Board has turned down the proposal to abandon the East-West Metro ventilation shaft at Raja Subodh Mullick Square. On Friday, Kolkata Metro Rail Corporation (KMRC) convened a meeting with ITD officials to share the views of its board of directors on the decisions taken on the way forward. The board wants ITD to find alternative ways to link the vent shaft because the time and the crores of public funds spent on the shaft construction must be accounted for, especially since the primary funding agency for the project is Jica.
In tandem with the National Building Code of India and the US-based National Fire Protection Association rules, KMRC Board has approved an evacuation shaft on Bowbazar’s Durga Pituri Lane to replace the first three contentious cross passages from the Sealdah side. Construction of cross passage 2, below Bowbazar’s Madan Dutta Lane, had caused the third East-West Metro-related subsidence at Bowbazar on October 14. There are eight passages planned along the Esplanade-Sealdah section.

ITD ITD-Cementation, contracted to build the last 2.5km leg of East-West Metro, has given up work of linking the twin tunnels below Nirmal Chunder Street, fearing fresh subsidence. Since April 1, work to join the twin tunnels with the vent shaft at Subodh Mullick Square was underway, but slowed down considerably after the two setbacks – cave-ins on May 11 and October 14. Subsequently, ITD had soil tests done and identified the grounds inside the Technical School campus on SN Banerjee Road as the ideal location for a new ventilation shaft and then joined it with the twin tunnels.
On Friday, the above proposal’s rejection was made known to ITD. “We told them categorically that work has to restart at the same location. They must come up with an alternative method of ground improvement, like ground freezing, at the same site (Nirmal Chunder Street) and then join the twin tunnels with the already constructed vent shaft at Subodh Mullick Square,” a senior KMRC official said.
The ventilation shaft is meant to boost air circulation in tunnels between stations. Work to join it with the twin tunnels running below Nirmal Chunder Street started in April, last year. But Nirmal Chunder Street and Subodh Mullick Square fall in the same cave-in zone as Bowbazar’s Durga Pituri Lane where houses fell in a subsidence on August 31, 2019. Even after extensive grouting, the ground at Nirmal Chunder Street did not improve.
KMRC wants the ground strengthening solutions to be implemented immediately so that the corridor’s final 7km run below the Hooghly can start next year.
The 4.8km Esplanade-Howrah Maidan section is ready, but the Rs 9,000-crore project is saddled with subsidence issues between Sealdah and Esplanade. The line now operates 9km from Sector V to Sealdah. KMRC was eyeing a December 2023 date to complete the entire 16km, but now there’s a fresh question mark on this revised deadline, as well.
The KMRC official explained, “We are running out of time. At the time we are looking at commissioning the entire 16km till Howrah Maidan below the Hooghly, it’s too late to locate a new site and drop a complex construction like the ventilation shaft at Subodh Mullick Square after spending nearly three years on it.”

Source: https://news.google.com/__i/rss/rd/articles/CBMijgFodHRwczovL3RpbWVzb2ZpbmRpYS5pbmRpYXRpbWVzLmNvbS9jaXR5L2tvbGthdGEva29sa2F0YS1tZXRyby1yYWlsLWNvcnBvcmF0aW9uLW5vLXRvLWUtdy1zaGFmdC1zaGlmdC1mcm9tLXdlbGxpbmd0b24vYXJ0aWNsZXNob3cvOTc0MDkzMzcuY21z0gGJAWh0dHBzOi8vbS50aW1lc29maW5kaWEuY29tL2NpdHkva29sa2F0YS9rb2xrYXRhLW1ldHJvLXJhaWwtY29ycG9yYXRpb24tbm8tdG8tZS13LXNoYWZ0LXNoaWZ0LWZyb20td2VsbGluZ3Rvbi9hbXBfYXJ0aWNsZXNob3cvOTc0MDkzMzcuY21z?oc=5