BENGALURU: A building erected on an unused old well gave way on Thursday morning when the Bengaluru Metro’s Tunnel Boring Machine 'Bhadra' was tunnelling from the upcoming Venkateshpura Metro station towards Tannery Road station, bringing work to an abrupt halt. A family of five residing there has been evacuated.
Bhadra is one of the nine TBMs being deployed to create a 13.92 km underground corridor for the Nagawara-Kalena Agrahara Line (Pink Line). The machine, which began boring underground on June 18, is scheduled to tunnel a total distance of 850 metres.
A senior official of the Bangalore Metro Rail Corporation Limited said, “The TBM had completed nearly 110 metres of tunnelling when a sinkhole appeared around 7.30 am today. This is because of an old open well which had been closed and on top of which a building had been constructed.”
An official release said that a chicken shop was functioning on the ground floor while a family of five members was residing in a house on the first floor. “To ensure safety, the shop has been closed and the family had been provided accomodation near Nagawara,” said an official release.
The official added, “We have filled the sinkhole with concrete and sand after the incident. It has been completed and it has to settle down which would take a few days. We will restart the tunnelling after that.”
Problems due to tunnelling, which is carried out over 60 feet below the ground, have plagued work on the Bengaluru Metro. TBM 'Urja' which was the first to achieve a breakthrough on September 22 had to stop tunnelling a few times due to slurry and water rushing into the houses and shops above. Tunnelling issues delayed the Metro Phase-I project by over a year when TBM Godavari stopped work completely as its cutter head broke and spare parts had to be brought from Italy to restart operations. Another sinkhole was caused on a busy road at KR Market during drilling.