E-Paper
Shivajinagar-Swargate metro underground work on its way to completion
Maximum tunnel depth which is 30 metres will be at the civil court station; it will take 2 years to complete the 10-km stretch, say officials
The construction work on the Pune metro underground line has commenced. The gigantic tunnel boring machine (TBM) started digging the 100-metre underground tunnel of Shivajinagar-Swargate metro. According to the officials the maximum tunnel depth which is 30 metres will be at the civil court station.
In a field visit organised by the Maharashtra Metro Rail Corporation Limited (Maha-Metro) on Monday, Atul Gadgil, director (works), Pune metro said, “We have completed around 80 metres of the 10-km stretch from Agriculture College to Swargate. It will take us at least two years to complete the entire 10-km stretch.”
An onsite engineer working on the tunnel boring machine said, “It takes four revolutions per minute for the cutter to move ahead, cutting around 18-20 mm of the hard rock per minute. We started digging at 18 metres (55-foot below ground level), however, there will be a gradual descent and the maximum tunnel depth which is 30 metres will be at the civil court station.”
According to Hemant Sonawane, general manager, public relations, Pune metro, there will be four machines to help finish the tunnel till Swargate. “Currently there are two tunnel boring machines that are presently working at Agriculture College ground, while two more machines will start digging the tunnel from Swargate in March 2020. Hence, four tunnel boring machines will be used to dig the 10-km underground tunnel,” he said.
The tunnel boring machine trials began on December 9. The machine is 279 feet in length, including backup gantry with the cutter head which is used for boring while the machine moves ahead with help of a thrust and steel jacks surrounding the cutter head. The pre-cast ring is of 1.4 metres in width. The engineers run seven-eight rings maximum in 24 hours and 16 jacks push the cutter head, according to officials.
The Pune metro underground line runs from Shivajinagar to Swargate and includes five stations — Agriculture College (18 metres), Civil Court (28 metres), Budhwar peth (25 metres), Mandai (20 metres) and Swargate (22 metres).
Tunnel boring machine (TBM) fact file
TBM manufacture: TERRATEC
TBM shield length: 10.115 m
TBM backup length: 90.00 m
TBM shield weight: 450 tonnes
TBM cutting diameter: 6.650 m
Overall length of TBM: 100 m
Tunnel final finish diameter: 5.80 m
TBM cutterhead weight: 54 tonnes
