After Helen and Margarita, the two tunnel boring machines (TBMs) now being used along the East-West corridor of the Namma Metro project, the Bangalore Metro Rail Corporation (BMRCL) has deployed another pair of TBMs, Seli and Herenknecht, on the North-South corridor.
The new TBMs have started work at KR Market to launch the south ramp, which is part of the underground section of the four-km long North-South corridor between Sampige Road and the National College, Basavanagudi.
A senior official from the BMRCL said the temporary tunnel ring erection for the first TBM is almost over and that for the second one is under progress.
Secant piling work is in progress for the north ramp and excavation of 13,507 cubic metre (cum) of sand has been completed out of the required 27,689 cum. “Erection of gantry crane soil anchoring work is in progress.
At Chickpet, out of 848 secant piles, 703 have been completed. Station excavation of 15,455 cum has also been completed. At KR Market, 777 secant piles have been completed, out of the 866. Temporary steel decking for KR Road is in progress. A total of 573 tunnel rings have been cast, out of 3,384, at Hesaraghatta casting yard,” he said.
TBM 1 (Helen) and TBM 2 (Margarita) are being used for tunnel boring from Sir M Visvesvaraya station towards the Vidhana Soudha station in the underground section of 4.8- km East-West corridor (between M Chinnaswamy Cricket Stadium and Magadi Road).
“Helen has progressed up to 483 m and Margarita has gone up to 351 m. TBM 3 between Cubbon Park and the East ramp has completed east-bound tunnel and 24 m of West-bound tunnel,” he added.
At the underground work of Majestic interchange station, secant piling work of 1,790 numbers has been completed out of 1,948. Temporary road decking work at Dharmambudi Road and Gubbi Thotadappa Road is in progress, the official said.
The Reach-4 stretch between KR Market and RV Road on the elevated stretch is also progressing and 98 per cent of the viaduct work has been completed. The overall progress of station work is also good at 80 per cent.
However, in other corridors, work needs to gain pace and, in some stretches, the BMRCL is yet to take possession of the land for the construction. For instance, along Reach 3a (Yeshwantpur to Peenya Depot), the number of properties proposed for possession is 122. However, the Corporation has been able to take possession of only 81 properties, while 77 of the properties in possession have been demolished to create space for the construction.
Along Reach–2 (Magadi Road to Mysore Road Terminal), 94 per cent of the work on viaduct and 60 per cent of the work on stations have been completed. On Reach–3 (Swastik to Yeshwantpur), 67 per cent of work is completed at Yeshwantpur, Soap Factory, Mahalakshmi stations and 64 per cent of work is completed on Rajajinagar, Kuvempu Road and Srirampuram stations. Along Reach–4a (RV Road to Puttenahalli Cross), overall progress is 79 per cent in viaduct construction.