The GMLR tunnel project in Mumbai has completed 64 metres of excavation on its first underground tunnel, while the second tunnel-boring machine is expected to undergo testing in October, the Brihanmumbai Municipal Corporation said on Thursday.
The Phase 3B section of the Goregaon-Mulund Link Road involves twin underground tunnels connecting Dadasaheb Phalke Chitranagari, commonly known as Film City, in Goregaon East with Amar Nagar in Mulund West. The tunnels will pass beneath the Sanjay Gandhi National Park and are designed to carry three lanes each.
The first tunnel-boring machine, named Tulshi, was commissioned on August 17 and has completed 64 metres of excavation. The work has also involved installing 27 ring segments and two temporary ring segments as part of the tunnel lining process.
The second machine, named Vihar, is 92 per cent assembled, according to the BMC. Its Site Acceptance Test is scheduled to begin on October 13 after the complete system is installed. Subject to successful technical tests, excavation of the second tunnel is expected to start on October 22.
Additional Municipal Commissioner (Projects) Abhijit Bangar inspected the site on Thursday to review excavation, construction activity, machinery performance, safety arrangements and construction quality. He also examined the manpower and technical requirements needed to maintain the project schedule.
The two parallel tunnels are each 4.70 kilometres long. Their diameter is 14.20 metres, while the section passing through the Sanjay Gandhi National Park has a diameter of 13 metres. The Tulshi machine is a single-shield Earth Pressure Balance hard-rock TBM, with a cutter diameter of 14.49 metres and a total length of 83 metres, including its shield and backup gantry.
The machine has an automated muck-handling system comprising a 340-metre conveyor system, a cross conveyor and a stacker conveyor. The BMC said the system is intended to support muck removal, improve productivity and make excavation safer in challenging geological conditions.
Bangar directed officials to prepare a dashboard showing the percentage of work completed, current project status, excavation progress, daily excavation targets, expected completion, safety measures and the project schedule. The dashboard is intended to provide officials and engineers with a consolidated view of construction progress.
He also instructed the agencies involved to review excavation rates, machinery, technical requirements and manpower regularly, and to deploy additional technical staff wherever necessary. The BMC said worker and engineer safety must remain a priority and directed teams to follow prescribed safety standards, maintain safety equipment and introduce preventive measures after assessing risks.
The GMLR project is targeted for completion by February 2029. The civic administration has directed the agencies involved to coordinate their work and maintain progress towards that deadline.
