look news india
Golden Metro: Delhi Metro has completed construction of a 2.65 km long tunnel in South Delhi, the longest tunnel of Phase IV. In fact, Delhi Metro Rail Corporation (DMRC) has achieved an important achievement today by completing the construction of the longest underground tunnel under Phase 4. This tunnel has been built between Tughlaqabad-Air Force Launching Shaft and Ma Anandamayi Marg, which is part of Tughlaqabad-Aircity Corridor of Phase-IV.
The success of Tunnel Boring Machine (TBM) ‘Amrit’ at Maa Anandamayi Marg site was celebrated in the presence of DMRC Director Projects & Planning Rajeev Dhankhar and other senior officials. This tunnel boring machine reached Maa Anandamayi Marg station this morning after digging a 2.65 km long tunnel.
This tunnel is made with a 105 meter long boring machine.
This tunnel has been built with the help of a giant 105 meter long TBM. Two parallel circular tunnels are being constructed on this section, with up and down movement. The second parallel tunnel is to be completed in January 2025. This project has been built with the help of a private company named Afcons. This new tunnel has been constructed at an average depth of about 16 meters. About 1894 rings have been installed in the tunnel, whose internal diameter is 5.8 meters.
The work of tunneling was technically challenging, involving difficulties such as shifting sewer lines, passing through hard rock. The tunnel is constructed using EPBM (Earth Pressure Balancing Method) technology with concrete lining of precast tunnel rings. These tunnel rings were fabricated in a fully mechanized casting yard at Mundka.
All necessary safety measures were adopted during construction. Ground movements were monitored through highly sensitive instruments to ensure that no sediment settled. So far, 40.109 km of underground lines are being constructed under the approved Phase 4 work. The Aircity-Tughlaqabad corridor comprises a total of 19.343 km underground stretch.
TBMs are used to excavate circular segmented tunnels through various soil and rock layers. These machines have currently revolutionized tunneling, making it possible to build tunnels without affecting surface structures and buildings. DMRC has used TBMs for its tunneling work since Phase 1, especially in congested urban areas. In Phase 3, when about 50 kilometers of underground sections were built, about 30 TBMs were deployed in the country’s capital.