PUNE: Work in the underground section of the Pune Metro railroad is expected to begin in June. The Maharashtra Metro Rail Corporation (Maha Metro) will issue tenders in this regard in a week.
The underground section is 5 km long and is located below the Pimpri-Swargate metro corridor. At Rs500 crore per kilometer, the underground work is expected to cost 2,500 rupees.
“Once the bids are issued, bidders are allowed a period of 45 days to participate, followed by the process of opening tenders and issuing work orders and after that, field work begins,” said MahaMetro’s boss, Brijesh Dixit.
Dixit added that the bidding process will be open for both Indian and foreign companies. “There will be a good amount of competition since several companies have the necessary tunnel technology for the underground subway,” he said.
The total length of the Pimpri-Swargate corridor is 16.5km, of which the last 5km will be underground. In this section, nine of the 15 stations will be elevated and the rest underground.
According to the Maha Metro plan, most of the area where the underground work will be carried out is built or passed below the main roads. Therefore, vertical axes will be inserted into the college of agriculture and Swargate, and the tunnel boring machines (TBM) will be lowered through the axles to excavate an important part of the route.
Authorities said there are smaller sections in the underground part of the alignment where a “cut and cover” method is being considered.
“To begin with, work will be carried out in the wells,” said a senior MahaMetro official. “These axes, one in Swargate and the other in the university of agriculture, will be used to lower the TBM, Tunnel excavators will start operating in five or six months,” the official added.
The tunnel boring machines will excavate the tunnel at the sites where the Metro stations for Civil Court, Pune Municipal Corporation, Budhwar Peth and Mandai will be installed, while the cutting and coverage method will be used at the Shivajinagar and Swargate stations.
Stripped to the bone, the structure of the metro station is a concrete box about 20 m wide, 14.6 m high and 225 m long, with an intermediate slab. The sides of the box are made of reinforced cement 1.2m thick.
When asked about possible damages to public services, officials said that the guidelines in the detailed project report (DPR) will be followed to the letter. “All public services that fall within the excavation area must be diverted in advance to avoid damage during construction, but cross-profits must be supported,” said DPR.
A suggestion made by the consultants for the project indicates that the pressure water ducts crossing the proposed cutting zone must be provided with valves on both sides of the cut. This will serve to isolate the cutting and flooding area in case of damage to the pipeline while the work is being carried out.