Australian-based TBM manufacturer, TERRATEC, recently joined workers and officials from Gulermak–TATA Projects JV and the Lucknow Metro Rail Corporation (LMRC) to celebrate the successful completion of the city’s first TBM-driven tunnels, as part of the the 22.88-km long (Phase 1 A) Lucknow Metro North-South line.
The first of two 6.52-m diameter TERRATEC earth pressure balance (EPB) machines working on the project, the S52 TBM named “Gomti,” was launched from Sachivalaya Station’s Bapu Bhawan Shaft in January. It took Gomti just four months to complete the first down-line tunnel on the line’s 3.44-km LKCC-06 underground section, arriving at Hazratganj Station in late May. Following a 2.5-month wait for the official ceremony, the TBM broke through the station wall on Aug. 7, followed a day later by its sister machine, the S53 TBM named “Ganga,” on the up-line tunnel.
The EPB machines feature a classic soil configuration and are equipped with a spoke-style cutterhead with a 57 percent opening ratio. TERRATEC has designed the cutterheads with cutting tools that are interchangeable with 17-in. roller disc cutters, allowing the TBMs to bore through station D-walls and cope with the presence of any unexpected obstacles in the ground.
The TBMs mined through geology consisting of stiff to hard clayey silt and medium to dense silty sand, passing beneath historic buildings in the Capital Plaza of Hazratganj (heritage district) without any disturbance to buildings, public utilities or traffic.
Speaking at the ceremony, LMRC’s Managing Director, Mr. Kumar Keshav said: “This unique achievement was only possible due to the hard work and commitment of the Lucknow Metro project team. The tunneling in this stretch posed an enormous technical challenge as the route passes beneath highly congested areas at a depth of 12 to 15 m below ground. With this breakthrough, LMRC has achieved one of the biggest milestones in form of completion of first TBM drive in the construction of underground metro in the state of Uttar Pradesh.”
Added TATA Projects’ Managing DirectorMr. Vinayak Deshpande: “Due to many heritage structures, the stretch was highly challenging. With excellent guidance from the LMRC team, state-of-the-art TBMs, and a dedicated, passionate, project team, the daunting task was completed in a world-class manner with outstanding quality and before-time completion. We all at TATA projects feel very proud of this accomplishment.”
With tunneling work completed between Sachivalaya and Hazratganj stations, there are now four tunnel drives (and breakthroughs) remaining. The TBMs are currently being reassembled at the Sachivalaya (State Secretariat) Station’s western-end to build twin 613-m tunnels toward Hussainganj Station. From there, the TBMs will continue on a further 419 m – crossing underneath the Haide Nalah (canal) – to a cut-and-cover ramp near Charbagh station.
The 36-month EPC (Engineering, Procurement, Construction) contract, which was awarded to TATA-Gulermak JV in April 2016, also includes the construction of three new underground stations at Hussainganj, State Secretariat (Sachivalaya) and Hazratganj.
Lucknow is the capital of Uttar Pradesh, the most populated state in India. The city’s rapid growth combined with substantial traffic congestion has prompted the need for a modern public transportation system. Aiming to bring world-class infrastructure to the city, Phase 1 of the two-line Lucknow Metro system is being built at a cost of 6,928 crore ($1 billion USD). Phase 2 of the system is due to commence in 2018.