New Delhi, Jul 29 (PTI) The Delhi Metro Rail Corporation (DMRC) on Tuesday achieved a milestone in its Phase 4 expansion work with a tunnel breakthrough on the Tughlakabad–Aerocity corridor, a statement said.
A Tunnel Boring Machine (TBM) completed the excavation of a 792-metre underground stretch between Tughlakabad and Tughlakabad Railway Colony.
The breakthrough took place at the railway colony station site in the presence of Railway Board Member (Infrastructure) Naveen Gulati and senior DMRC officials, according to a statement.
The tunnel, built at an average depth of 18 metres, was constructed using Earth Pressure Balancing Method (EPBM) technology. The 91-metre-long TBM installed 559 concrete rings during the process, with each ring having an internal diameter of 5.8 metres, the DMRC said in the statement.
The tunnel lining was made using precast concrete segments manufactured at a mechanised casting yard in Mundka and steam-cured for early strength, it said.
The DMRC said that special precautions were taken during the underground work to avoid any disturbance to the surrounding buildings.
Ground movement was closely monitored through precision instruments to ensure structural safety in the area, it said.
The DMRC said the project is being executed by Afcons Infrastructure Ltd, one of the contractors appointed for Phase 4 construction.
The Aerocity–Tughlakabad corridor features a total of 19.343 kilometres of underground stretches, out of the 40.109 kilometres of underground alignment planned under phase 4, it read.
The DMRC has been using TBMs since its first phase to construct underground sections without disturbing existing surface structures, a method particularly suited for congested urban areas.
The agency deployed around 30 TBMs across the city during Phase 3, which included nearly 50 kilometres of underground work.
DMRC achieves tunnel breakthrough on Phase 4's Golden Line at Tughlakabad
PTI
Updated: July 29, 2025 18:48 IST
(This story has not been edited by THE WEEK and is auto-generated from PTI)
