BENGALURU: Tunnel Boring Machine (TBM) `Bhadra’ which had stopped tunnelling work on September 30 due to a sink hole has now resumed operations in a very slow fashion. The TBM was tunnelling from Venkateshpura to Tannery Road Metro stations when a sinkhole appeared at a spot 110 metres from its originating point last Thursday.
A family of four was evacuated and a chicken shop was closed on account of the sink hole.
Bangalore Metro Rail Corporation Limited (BMRCL) Managing Director Anjum Parwez told TNIE, “Bhadra resumed tunnelling on Tuesday but was operating very slowly.”
A senior Metro official said, “We have taken adequate precautions and those at the site are monitoring the tunnelling very closely. The boring work commenced early morning on Tuesday and continued today (Wednesday) but at a very slow speed. We have tunnelled just 1.5 metres in two days.”
Bhadra, which started operations on June 17, needs to tunnel around 850 metres to touch Tannery Road. It is one of the nine TBMs which are deployed over 60-feet below the ground to ready a 13.92-km underground corridor for the Nagawara-Kalena Agrahara Line (Pink Line). The sink hole had occurred due to the collapse of the wall of an old well which had been closed with a building constructed above.
The affected family that was provided alternate accommodation continues to stay there.
Interval for Tunga
The other TBM Tunga, also tunnelling from Venkateshpura station (in the North direction) since June 16 this year, has completed 65 rings and has temporarily stopped its drilling work. “We need to ready a few structures so that the tunnelling work can proceed further. Those are being readied underground now,” the official said.