The Delhi Metro Rail Corporation (DMRC) has celebrated a construction milestone with the completion of the longest tunnelling drive for Delhi Metro Phase IV.
TBM Amrit, operated by Afcons Infrastructure, broke through yesterday, completing the bore between the Tughlakabad Airforce launch shaft and Maa Anandmayee Marg Station on the Tughlakabad-Aerocity corridor.
The tunnel has been constructed at an average depth of approximately 16m, with around 1,894 rings installed, each with an inner diameter of 5.8m. The rings were cast at a fully mechanised casting yard at Mundka. The concrete segments were cured with steam to achieve early strength.
“TBM Amrit successfully completed 2.65 km of boring through mixed soil and hard rock strata today. It is the longest tunnelling drive in Phase-IV of Delhi Metro. Frequent cutter replacements were required to bore through the hard rock. The tunnel drive alignment was meticulously planned to avoid passing beneath heritage structures adjacent to Mehrauli Badarpur Road,” said Afcons managing director S Paramasivan.
Two parallel tunnels are being constructed along this stretch of the Aerocity-Tughlakabad corridor. The breakthrough on the second tunnel is expected in January.
TBM Armit, a 6.5m-diameter refurbished Robbins EPBM, was launched in May 2023. It was the first of four machines to be deployed by Afcons to build the twin tunnels on the 6.9km-long DC-07 package between Sangam Vihar Station and Sarita Vihar Depot.
DC-07 includes three stations, 11.26km of tunnelling, a 223m ramp, and a 119m cut-and-cover section. The three underground stations are Maa Anandmayee Marg Station, Tughlakabad Railway Colony Station, and Tughlakabad Station.
As part of the Phase 4 work approved so far, 40.1km of underground lines are being constructed. The Aerocity-Tughlakabad corridor has underground sections totalling 19.34km.
