Following successful factory acceptance tests, the first two Terratec 6.6m EPBMs are being delivered to the Gulermak-Tata Projects JV for its underground works contracts on Line 1 of the Pune Metro project, in Maharashtra State, India.

Terratec TBMs successfully factory tested

Earlier this year, Maharashtra Metro Rail Corporation (MahaMetro) announced that the joint venture had won both packages of the twin-tube underground alignment of the new 16.6km north-south metro corridor. The 5km underground section with five underground stations that runs from the College of Agriculture in Shivajinagar to Swargate, is considered the most challenging portion of the line, as it passes under the densely populated areas of Kasba Peth, Budhwar Peth and Mandai market.

"We are now ready to launch the first two Terratec TBMs,” said Ashish Dwivedi, Geotechnical Manager for the Gulermak-Tata Projects JV. “Terratec TBMs have a successful track record in India with seven currently working on the Mumbai Metro, and we expect to complete our 5km Pune Metro Line 1 twin tube excavation within the project schedule." Major challenges on the project will include passing beneath century-old surface structures, crossing under the River Mutha and launching and retrieving TBMs with limited access in the built up areas near Budhwarpeth and Mandai Stations.

Robust dome style mixed face cutterheads

Terratec EPBMs have robust mixed-face dome-style cutterheads designed to work effectively in the compact basalt that is expected on the alignment of the two contracts.

As the TBMs progress, they will operate at pressures of up to 4 bar and will install 1.4m wide x 275mm thick rings of precast concrete lining, consisting of five segments plus a key in each ring.

The TBMs will be transported to Pune where they will be assembled and then tested on site in mid-December. Pune is an industrial city that has witnessed much growth in the areas of corporate and industrial infrastructure over the last decade. Existing roads in the city currently carry an average of 8,000 commuters an hour in each direction and the city experiences hours of traffic jams during peak hours that leads to increased pollution.

The Pune Metro aims to provide a solution to the issues by offering a safe and eco-friendly journey with a 50% reduction in travel time. When complete, in 2022, the Pune Metro network will comprise three rail corridors with a total length of 54.5km.

Factory acceptance of the first of three Terratec 6.6m diameter EPBs for the Pune Metro in India is imminent and follows a major funding milestone for the project signed off by the European Investment Bank. The two other Terratec TBMs for the project are currently being manufactured at the company assembly plant in Nansha district, Guangzhou, in Guangdong province, China, reported Terratec to TunnelTalk.

First TBM ready for Pune Metro

With two lines in development, the project is constructing a total 31.3km network with 30 stations. The budget for the complete project is almost €1.8 billion (US$1.9 billion). A major development for the project is agreement by the European Investment Bank of a loan of €600 million (US$657 million). A third of the loan has been released to the developer, Maharashtra Metro Rail Corporation, which is a JV between the India Central Government and the State Government of Maharashtra. Additional funding of €245 million (US$268 million) is being supplied by the French Development Agency.

The underground alignment is on the north-south Line 1. The 16.6km route includes 14 stations between Pimpri-Chinchwad and Swargate, with about 30% running underground.

Contractor for the 5km underground portion is the JV of Gulermak of Turkey and Tata Projects of India, which was awarded two tunnelling lots in December 2018 and February 2019. Four TBMs, supplied by Terratec, were envisaged originally for the two underground contracts but the number has been reduced to three, Terratec informed TunnelTalk. The Gulermak/Tata JV worked on the metro project in Lucknow, a project also with EIB funding support.

The underground section of the twin-tube route runs north to south from Shivaji Nagar to Swargate and includes a total of five stations. The two contracts split the underground work into the:

• North lot that includes design and construction of the Shivaji Nagar and Civil Court underground Stations plus tunnels between Agricultural College and the north end of Budhwar Peth Station (Fig 1) and the
• South lot that involves design and construction of underground stations at Budhwar Peth, Mandai and Swargate, as well as the remaining twin tube tunnels.

Local contractor Kumar Infraprojects was awarded a works package in mid-2018 to perform shaft access works at Agricultural College and Swargate, where it will also construct the multimodal transportation hub on top of the underground station built by the Gulermak-Tata JV. Consultancy services to the client for Line 1 are provided by Systra, AECOM, EGIS and RITES. Construction began in late 2016 and is planned to be completed in 2021-22.