Delhi Metro completes longest tunnel stretch

NEW DELHI: The Delhi Metro Rail Corporation (DMRC) has completed the longest underground tunnel on the Tughlakabad-Aerocity corridor of Phase-IV, with a 2.65 km tunnel boring breakthrough at Maa Anandmayee Marg. A 105-metre-long tunnel boring machine (TBM) achieved the breakthrough on Wednesday.

Two parallel tunnels are being built on this stretch, with the second expected to be completed by January 2025. The tunnel, constructed 16 metres deep, features 1,894 precast concrete rings with an inner diameter of 5.8 metres. Technical challenges included the relocation of a sewer line and tunnelling through hard rock. Built using Earth Pressure Balancing Method (EPBM), the tunnel was lined with steam-cured concrete segments. Extensive safety measures ensured no settlement during construction. As part of Phase IV, the DMRC is constructing 40.109 km of underground lines, with the Aerocity-Tughlakabad corridor comprising 19.343 km

of this total.