BENGALURU: After a sinkhole appeared on Thursday, injuring a motorist and causing massive traffic jams in central part of the city, BMRCL top officials including its MD Anjum Parwez strongly ruled out possibility of the two Tunnel Boring Machines (TBMs) just below the sinkhole being the cause of the accident.
Parwez told TNIE, “The TBM has moved completely in rock. It has not touched soil. Moreover, it completed its work at the spot five days ago.” A senior engineer said that TBM Lavi had tunnelled 20m below the ground during its work from MG Road to Vellara Junction. “The distance between the TBM and the ground was 10.5m with 3m of rock above the tunnelled portion. The cavity had water in it, and if the TBM was responsible, the water would have gone into the tunnel,” he said. TBM Avni, which had also passed below this spot, had completed its job on October 21, he said.
There are plenty of sinkholes on roads across the city where no tunnelling activity is under way, said another official. Locals and shopkeepers at the spot recalled repeated incidents of water leaks in the area. A source, who was involved in the survey of the area before tunnelling began, said, “An old BWSSB pipeline of 450 mm in diameter runs for a distance of 2km below the ground from Johnson Market to Halasuru via the median of Brigade Road.
This could be the reason that water drips and it may have caused a cavity suddenly.” BWSSB assistant executive engineer at Halasuru sub-division, K Nagaraja told TNIE, “A water pipeline dating back to 1975 runs from Vellara Junction to Lifestyle junction, Commissionerate Road, Thimmaiah Road and reaches Halasuru. It does not pass below the Brigade Road.” BWSSB Chairman N Jayaram or the public relations team did not respond to calls. Engineer-in-chief BS Prahalad said, “If BBMP is asked to check and fill the stretch due to loose soil, it will do it with necessary materials.”