NEW DELHI: The Delhi Metro Rail Corporation (DMRC) has begun the first ever lowering work on the Tunnel Boring Machine (TBM) at Vikaspuri on the Janakpuri West—RK Ashram Marg of Phase IV corridor. As part of this tunnelling drive, two tunnels (for up and down movement) of a length of 1.4 kilometres will be bored between Vikaspuri and Krishna Park Extension.
These tunnels will be located between the Janakpuri West and Krishna Park Extension stations of the corridor. The tunnelling will start from Vikaspuri area in continuation of the Magenta line tunnel that has been already constructed for the presently operational Botanical Garden – Janakpuri West corridor.
The tunnelling work with the TBM is expected to start next month, after the lowering and assembling of the giant 73-metre-long machine is completed, said DMRC official. The tunnel will be constructed approximately at a depth of 14 to 16 metres. About 2,040 concrete rings will be installed in these tunnels.”
Each tunnel will have an inner diameter of 5.8 metres.
The entire tunnelling work on this stretch is expected to be completed in about 15 months. The alignment of the tunnel will be along the Outer Ring Road,” said Anuj Dayal, Executive Director (ED) of Corporate Communication, DMRC.
A TBM, is a machine used to excavate tunnels with a circular cross-section through a variety of soil and rock strata. They can be designed to bore through anything from hard rock to sand. TBMs have revolutionised the way tunnelling work is done all over the world as now tunnels can be bored without disturbing the buildings and other structures on the surface.
TBMs are especially useful for underground tunnelling work in congested urban areas. DMRC has been using TBMs for its tunnelling work since Phase I. In Phase III, when about 50km of underground sections were built, about 30 TBMs were pressed into service in the national capital, said DMRC official.
Metro’s phase IV
The Janakpuri West–RK Ashram Marg corridor will have underground sections of 7.74 kilometres in total. About 27 kilometres of underground lines will be constructed in the corridor under Metro’s phase-IV