en.Wedoany.com Reported - TERRATEC's 6.61 m diameter Earth Pressure Balance Machine (EPBM) "Narayani" has completed its tunnel drive on the Aerocity–Tughlakabad Silver Line (Line 10) of the Delhi Metro Phase 4, achieving a 1,600 m breakthrough on the Vasant Kunj–Mahipalpur section, successfully traversing extremely hard rock formations with a Uniaxial Compressive Strength (UCS) exceeding 200 MPa.
The drive is part of the DC-08 contract package of the Delhi Rapid Rail Transit System Phase 4 project, executed by J.Kumar Infraprojects Ltd. for the Delhi Metro Rail Corporation (DMRC). This marks the first drive completed by "Narayani" along this line.
During the drive, the 6.61 m diameter EPBM installed 1,400 mm wide universal reinforced concrete lining rings, each comprising five segments plus one key segment, providing structural support to the tunnel. Track-mounted battery locomotives were used for muck removal and segment transport to minimize the environmental impact of tunnel construction.
TERRATEC stated that the geological conditions on this section are among the most challenging strata in the entire Delhi Metro Phase 4 project. Portions of the alignment traverse extremely hard rock with a UCS exceeding 200 MPa, conditions more commonly encountered in hard-rock mining than in urban metro tunnelling. To address this, "Narayani" was equipped with a robust mixed-face cutterhead and hard-rock disc cutters to maintain advance rates under these geological conditions.
Once completed, the Aerocity–Tughlakabad corridor will strengthen metro connectivity in South Delhi by linking the airport area with major residential and commercial hubs, and will integrate with the Delhi Metro Phase 4 network to expand metro coverage.
TERRATEC has been involved in numerous major tunnelling projects across India, including Delhi Metro Phases 3 and 4, as well as metro projects in Lucknow, Pune, Kanpur, Ahmedabad, Mumbai, Surat, and Chennai, in addition to the Amar Mahal water supply tunnel. The company regards tailor-made TBM designs, site support, supply of TBM spare parts, and dedicated support during tunnelling operations as key elements of its project delivery approach.
