DMRC achieves second tunnel breakthrough at lal qila

The Delhi Metro Rail Corporation Ltd. is moving ahead at a fast pace and striving to achieve the completion of its Phase – III project as per schedule. Civil work on all the under-construction corridors is progressing at a rapid speed. Tunneling work is also nearing completion in most corridors. At present there are a total of 20 Tunnel Boring Machines (TBMs) functioning in all the under-construction corridors of DMRC.DMRC has achieved two tunnel breakthroughs in two consecutive days. Yesterday, DMRC achieved a tunnel breakthrough at Naraina by completing the tunneling on the under construction Delhi Cantt – Narina Vihar- Mayapuri of the Majlis Park – Shiv Vihar corridor, while , DMRC completed the tunneling on the Kashmere Gate – Lal Qila stretch of the Central Secretariat – Kashmere Gate Corridor by achieving a tunnel breakthrough of the second tunnel on the stretch.

The TBM emerged at Lal Qila metro station site after making a 1352 metre-long tunnel from Kashmere Gate. This TBM was lowered at Kashmere Gate shaft on 16th February 2015 and after assembly of the TBM below the ground the initial drive began on 04th April 2015. The maximum depth of the tunnel is 16 mts below the earth’s surface.The downline tunnel passed beneath the existing Kashmere Gate elevated Metro Station. The distance between the tunnel wall and Pile of the existing metro station is 0.8 metres. The tunnel also passed under a number of historical buildings and monuments like, the Dara Shikoh Library, Lothian Bridge (Delhi – Shahdara Northern Railway Line), The Grand Post Office, St. James Church and the Kashmere Gate Monument.

Earth Pressure Balancing Type TBM was used to construct the tunnel. A total of 970 rings have been inserted simultaneously along with the tunneling process. Each ring has five segments (each 275 mm thick) and the length of one segment is 1.4 mts. These segments and rings are connected by using bolts. The internal diameter of the tunnel is 5.8 mts. The casting of the segments was done at the Mundka Casting Yard. Approx. 51, 000 cu. mts. excavation was done in approx. nine months. The TBM used to make the tunnel is from Terratech.

M/s Metrostroy Era JV is the contractor for the tunneling work of the stretch from Kashmere Gate to Lal Qila metro station. The stations at Kashmere Gate and Lal Qila are also being constructed by the same contractor using Cut & Cover technique. The breakthrough of the first tunnel on this stretch was achieved on 03.08.2015.

This section is a part of the 9.37 km long Central Secretariat – Kashmere Gate corridor. The section from Central Secretariat to ITO which is 4.2 kms long is already operational for the general public.