BENGALURU: A massive sinkhole opened up on Thursday morning in a part of the Nagavara-KG Halli main road where metro rail tunnelling work is going on. According to Bangalore Metro Rail Corporation Limited (BMRCL) officials, the road caved in around 8.30 am. Following this, traffic to one side of the road was blocked and officials scampered to fill the gaping sinkhole.
BMRCL officials suspect that the road could have caved in due to water accumulation from Bangalore Water Supply and Sewerage Board (BWSSB) pipes underneath.
Ghouse Inamdar, Assistant Executive Engineer, Hennur Sub Division, said a 450-diameter water line and nine-inch sanitary line had suffered damage, and BMRCL has accepted to fix the pipelines. “The pipes suffered damage due to the metro tunnelling work and hence the road sank as the soil had become loose due to water accumulation,” said Inamdar.
BMRCL Chief Engineer Dayananda Shetty, who inspected the spot, said after being alerted about the sinkhole, earthmovers and workers were rushed to the spot. The sinkhole was filled with aggregates and the area has been sealed off.
“The traffic on one side of the stretch between KG Halli Road to Nagavara has been shut as the tunnel boring machine is just below the spot. Traffic will be allowed after consultation with the traffic police only after the machine moves away up to 10 metres from the spot,” said Shetty.
Another official said after the incident, the drilling operation was stopped. The TBM can drill up to 2 metres in length in a day if there is rock. In case of smooth or loose soil, the TBM can exceed up to 20 metres a day. Only after the concrete settles, traffic will be allowed. “The traffic on the stretch can be expected to open only by next week,” said an official.
In January 2023, a 3-metre wide sinkhole appeared on Brigade Road during the peak hour. At that time, a leak on a BWSSB pipeline was suspected to have caused the cave-in of the road. Drilling work had to be stopped for few days then too.