Lucknow begins metro TBM tunnelling 03 Nov 2016

Rapid urban growth of Lucknow city, the capital of most populated state in India, Uttar Pradesh, is progressing construction of a modern public transportation system to address and provide an alternative to substantial road traffic congestion. Aiming to bring world-class infrastructure to the city, Phase 1 of the two-line metro system is being built at a cost of 6,928 crore (about US$1 billion), with construction of Phase 2 due to start in 2018.

Underground section of Lucknow Phase 1A metro

With construction of Phase 1 underway, the Tata/Gulermak construction joint venture is taking delivery of the two 6.52m diameter Terratec EPBMs, for the Phase 1A North-South line. These are the first TBMs to be used in the city.

Following successful factory acceptance tests at a Terratec manufacturing facility in Delhi, the TBMs will be be transported to Lucknow and reassembled for the twin 1,812m long running tunnels on contract LKCC-06, which run from a ramp portal to the underground alignment near Charbagh Metro Station to the end of a to opposite surface transition ramp near KD Singh Babu Stadium Metro station (Fig 1).

The 36-month contract awarded to Tata-Gulermak JV in April 2016, includes the construction of three underground stations at Hussainganj, State Secretariat (Sachivalaya) and Hazratganj.

The first of the twin Terratec machines will be delivered to the Sachivalaya station site in mid-November, with the second expected to arrive in early December. The machines will be launched for the first 780m drives towards Hazratganj. They will work through geology consisting of stiff to hard clayey silt and medium to dense silty sand and under an average overburden of 4m to 10m.

The two Terratec machines are the first TBMs to be used in the city

As the drives progress, the machines will install a lining of 275mm thick x 1400mm long, reinforced concrete universal-style, precast concrete segments, comprising five segments and a key in each ring. The segments are being manufactured at a local casting yard in Vrindavan.

On the initial drives, the machines will pass beneath historic buildings in the Capital Plaza of Hazrat Ganj, and will will be retrieved at Hazratganj station box to be relaunched at the Sachivalaya station box for the 613m-long, drives towards Hussainganj. From there, they will continue a further 419m, crossing underneath the Haide Nalah canal, to the cut-and-cover transition ramp near Charbagh station.

57% open-ratio cutterhead will cope with clayey silt and silty sand

The EPB machines feature a classic soil configuration and are equipped with a spoke-style cutterhead with a 57% opening ratio. Terratec designed the cutterheads with interchangeable cutting tools with 17in disc cutters, allowing the TBMs to bore through station box diaphragm walls and cope with the presence of any unexpected obstacles in the ground.

Lucknow joins a growing list of cities in India that being supported by the National and State Governemtns to develop modern mass transit systems. Delhi, the most extensive and with the most alighnent underground; Kolkata, which is extending its system east under the river, Bangalore and Chennai have advanced systems with underground sections and Mumbai with a developed overground system is yet to agree and begin underground metro alignments. Other cities with aspirations and advanced plans for metro development include Kanpur, Patna, Jaipur, Ahmedabad, Pune, Surat, Indore, Nagpur, Kochi, Coimbatore, Kozhikode. The prospect of these projects moving into the construction stages will provide for visitors interested on the underground construction at the bauma CONEXPO trade fair to be held in Gurgaon/Delhi in December 2016.