BENGALURU: A unique feat was recorded by the Bengaluru Metro on Wednesday morning, when for the first time, a Tunnel Boring Machine (TBM) successfully drilled below a functioning Metro line. The feat was achieved by ‘Avni’, when it tunnelled under Cauvery Emporium on MG Road, thereby crossing the Metro alignment of the Purple Line.
On MG Road, the Metro line runs elevated with the road below, and the Undergound MG Road Metro station of the Nagawara-Kalena Agrahara line (Pink Line) will come further below the road. “On March 4, Avni began tunnelling from the South of MG Road Metro station and it drilled the 35 metres without any major hiccups,” a top source said. It had earlier spent 487 days tunnelling from Shivaji Nagar Metro station to MG Road, a 1,086-metre stretch that was completed on January 6.
Much preparation had preceded the successful completion of the exercise. “A special moveable barricade on wheels measuring 8 metres length, by 6 metres width, that can be shifted wherever required was readied. Having seen sink holes in the past during underground tunnelling, we decided to barricade the portion above the stretch being drilled,” said a reliable source.
“The idea was also to ensure minimum inconvenience to the public by barricading only a small portion,” he added. Recently, the Bangalore Metro Rail Corporation Limited also erected structures to offer support to the Emporium. In Phase-2, there will only be one more instance when such a tunnelling takes place, when Lavi, the TBM partnering Avni, crosses below the same stretch.
Avni will now proceed on its journey up to Vellara junction.