PUNE (Metro Rail News): The Maharashtra Metro Rail Corporation (MahaMetro) has finished digging an 18m-deep shaft at the College of Agriculture in Shivajinagar, marking the completion of a crucial step for the underground Metro rail section.
The shaft will be used to lower the tunnel-boring machines, which will excavate the tunnel for the underground route. A similar tunnel, 22m-deep, is being dug at Swargate.
MahaMetro had initiated civil work on this shaft about 12 months ago. “Controlled blast technology was used to break the hard rock beneath the surface after the soil layer was removed in the first stage of digging. The shaft is square in shape, measuring 25 meters wide on each side, and 18 meters deep,” a MahaMetro official said.
MahaMetro, which is executing two Metro routes in Pune and Pimpri Chinchwad — one from Vanaz to Ramwadi and the other from PCMC to Swargate — now plans to level the ground and construct a slab at the bottom to assist the landing of the tunnel-boring machines. “All the necessary provisions will be made in time to install the tunnel-boring machines and maintain the required depth.
Two parallel tunnels will be dug once the machines are lowered through the shaft,” an official said. MahaMetro expects to take delivery of the first tunnel-boring machine in October. The excavation of the tunnel is expected to begin in November.
“A team of MahaMetro officials will be visiting the Hong Kong-based company (which is providing the machines) to conduct various tests on the tunnel-boring machines,” an official said. Officials said that the tunnel-boring work will begin from two ends — agriculture college and Swargate.
The digging at the Swargate site is underway and has been expedited once MahaMetro cleared various hurdles related to the side. The Swargate shaft will be four meters deeper than the one at agriculture college. An official said the difference in depth was because of the condition of the soil, rock, and the requirements of the project.
“The difference will not affect the construction of the tunnel,” an official said. Both the tunnels will meet in Kasba Peth area, at the underground metro station. A MahaMetro official said that the work of digging the tunnel will first start from the agriculture college end and will be taken up later from the Swargate end. Meanwhile, MahaMetro said that it has taken elaborate measures to dump the soil extracted from the shaft at designated spots