DEHRADUN: With part of an under-construction tunnel collapsing in Uttarkashi on Sunday following landslides, trapping about 40 workers in its wake, operations are on to clear the debris and rescue them. All workers are safe and are being provided food and oxygen through pre-existing pipes.
The accident happened in the Silkyara side of the tunnel that would terminate at Barkot when it is complete. The Union road transport ministry said the caving in began at 5.30 am when about 40 workers were inside the tunnel doing reprofiling work 260-265 metre from the Silkyara portal. A collapse occurred between 205 metres and 260 metres, trapping all 40 workers, the statement said.
Rescue teams have cleared debris up to 28 metres; rubble from about 32 metres more needs to removed. The problem is fresh mud keeps falling as the rubble gets cleared. To prevent that, rescuers are doing what is called shotcreting (concrete spraying) with machines, which is a time-consuming process.
After discussions with experts and inspection of the behaviour of the fallen muck at the site, the Union ministry said it has been decided to push 3 ft diameter steel pipes through the rest of the debris with the help of a hydraulic jack to evacuate the workers.
The tunnel is quite wide. It has an excavated diameter of 15.3 metres and finished diameter of 12.77 metres. Parallelly, the National Highways and Infrastructure Development Corporation has recalled its former General Manager Colonel Deepak Patil, who was transferred to Jaipur from Uttarkashi just last week — on November 6 — to lead the rescue operations.
Col Patil had monitored the project for five years before his transfer. He will be airlifted from Dehradun to the Barkot disaster site on Tuesday morning. About 2,340 metres of the tunnel from the Silkyara side and 1,750 metres from Barkot side have already been built. Just 441 metres of the 4531-metre tunnel is yet to excavated.
The Silkyara-Barkot distance by road is about 25.6 km, which the tunnel aims to reduce to just 4.5 km, cutting travel time from 50 minutes to 5 minutes. It’s is part of the Chardham project for all-weather seamless connectivity for pilgrims.
District Magistrate Abhishek Rohilla said, “Health department teams are stationed at the tunnel gate with experts and proper medical equipment, ambulances. In case of any adverse situation, hospitals in adjoining districts and AIIMS Rishikesh have been put on high alert.”
Specialised machines
While excavation with shotcreting (concrete spraying) for 40 metres of collapsed tunnel has started, another shotcrete machine has been shifted to the work site, the Union road transport ministry said