Having delivered 22 TBMs to India in the last five years (more than any other manufacturer), TERRATEC continues to complete successful projects and in late-April provided more of the same as the Australian-based TBM manufacturer joined workers and officials from Gulermak-TATA Projects JV and the Lucknow Metro Rail Corporation (LMRC) to celebrate the 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 two 6.52m diameter TERRATEC earth pressure balance (EPB) machines, the S52 TBM named “Gomti” and the S53 TBM named “Ganga,” simultaneously broke through at Lucknow’s Hussainganj underground metro station on April 28, completing their third drives for the project, two months ahead of schedule. The event also marked the completion of tunneling works on the 3.67-km long Charbagh-Hazratganj underground stretch in approximately 15 months.
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.
The EPB machines feature a classic soil configuration with a spoke-style cutterhead and a 57 percent opening ratio. TERRATEC 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 unexpected obstacles in the ground.
However, tunneling through the heart of Lucknow posed a number of difficulties and engineers working on the project carefully planned every step involved in the tunneling operation. The final drives from Charbagh to Hussainganj were possibly the most challenging, as the TBMs had to pass 1 m below the bed of the Haider Nallah (canal) in a highly populated area full of dilapidated structures on weak foundations.
“During this journey, the TBMs delivered excellent performance, with no major breakdowns, crossing the Haider Nallah and so many other geological challenges along the way. We are very thankful to the entire Terratec team,” says Ramesh K., Assistant General Manager (P&M) with TATA Projects. “With these state-of-the-art TBMs, and a dedicated, passionate, project team, this daunting task was completed in a world-class manner with outstanding quality and before-time completion.”
These tunnels will now provide Lucknow – the capital of Uttar Pradesh – with its first underground metro line, bringing a modern public transportation system to a city that is currently experiencing rapid population growth and substantial traffic congestion. Phase 2 of the system is due to commence in 2018.
Meanwhile, Larsen & Toubro is gearing up to launch the first of two 6.57 m diameter earth pressure balance machines supplied by TERRATEC for Package 2 (East-West Corridor) of the 20.7-km long Line 1 of the Ahmedabad Metro, in western India.
Awarded by Metro-Link Express for Gandhinagar and Ahmedabad (MEGA) Company Ltd. in January 2016, the Package 2 contract includes the construction of 3.3 km of twin tube running tunnels between Kalupur Railway Station and Shahpur, two underground stations at Gheekanta and Shahpur, as well as cut-and-cover structures, NATM connections and launch and retrieval shafts for the TBMs.
The first of the two TBMs, S71, was expected to launch in May from a launch shaft located at Kalupur Station, with the S72 machine expected to follow sometime in June. The tunneling works are due to be complete by December 2019.
“In recent years, TERRATEC has emerged as one of the most dominant TBM suppliers in the Indian market, having supplied 22 TBMs in the last five years alone,” says Gulshan Gill, Managing Director of Terratec India. “Our clients repeatedly return to us, opting to select TERRATEC TBMs for their new projects due to the excellent performance of these machines, as witnessed by the tunneling fraternity in India. TERRATEC’s continuing success is a result of excellent tailor-made robust TBM design, prompt onsite assistance, a readily available stock of TBM spares, and highly-skilled specialized TBM support throughout the tunneling operation.”