TERRATEC TBM Celebrates Final Breakthrough on Pune Metro

On July 22, 2021, TERRATEC joined officials from Maharashtra Metro Rail Corporation Ltd. and workers from Gulermak-TATA Projects joint venture to celebrate the final breakthrough of a 6.61-m diameter TERRATEC Earth Pressure Balance (EPB) Machine, named “Mula,” on the Pune Metro Rail Project, in Maharashtra, India. The machine holed through into the underground Budhwar Peth Station on Pune Metro’s 16.56-km Line-1 (Purple Line).

The major milestone has seen Gulermak-TATA Projects JV complete one of the twin-tube tunnels between the Civil Court Station to Budhwar Peth Station down line which is 724.6 m in length. TERRATEC Earth Pressure Balance (EPB) Machine S79 has successfully crossed the river Mutha which was the major challenge of the project. This is the third metro project where TERRATEC TBMs have crossed a river. Last year, TERRATEC TBMs deployed by J. Kumar in Mumbai Metro Line-3 achieved a similar feat. Terratec field service team was present at the time to assist the JV to cross the river.

In September and November 2020, the two 6.61-m diameter TERRATEC Earth Pressure Balance (EPB) Machines, the S78 TBM named “Mutha” and the S79 TBM named “Mula” (named after the river Mutha and the river Mula), have broken through at the northern end of a 155-m scissor crossover, built by NATM at the start of Civil Court Station launched from near the College of Agriculture at the end of 2019, completing their second drives of the project. It was a great achievement considering the hard rock condition and being in a densely populated area.

In 2019, Maharashtra Metro Rail Corporation Ltd. (MahaMetro) announced that the joint venture had won both of the twin-tube tunnel packages Line 1 and Line 2 on the new 16.56-km long north-south metro corridor. The 5-km underground section – which runs from the College of Agriculture in Shivajinagar to Swargate and has five stations – 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. TERRATEC was selected by Gulermak-Tata Projects JV to deliver 3 TBMs for the underground works for both packages of the new Pune Metro Rail Project, in Maharashtra, India.

The TERRATEC EPBMs feature robust mixed-face dome-style cutterheads designed to work effectively in the compact basalt that is expected on these contracts with water pressures expected of up to 4 bar. As the TBMs progress, 1,400-mm wide by 275-mm thick precast concrete lining rings will be installed, which consist of five segments plus a key.

The S79 TBM named “Mula” excavated a total distance of 84 m below the river Mutha with approximately 10 m cover above the tunnel crown. Earlier, both the TBMs S78 and S79 broke through in a scissor crossover cavern 155 m in length. The TBMs were dragged and then moved to the other end of the Civil Court Station using hydraulic jacks over a distance of 280 m.

Meanwhile, the city’s third TBM, S81, has performed a site acceptance test for Pune Metro Line 1 UG-02 earlier in March at Swargate Station and will breakthrough into Mandai Station in the next weeks. Along with TBM S81, TBM S79 will then be transferred to work on package Line 1 UG-02.

TERRATEC’s continuing success on projects such as Phase III of the Delhi Metro, Lucknow Metro, Pune Metro, Ahmadabad Metro and Mumbai Metro is a result of tailor-made robust TBM design, prompt onsite assistance, readily available stock of TBM spares and highly-skilled specialized TBM support throughout tunneling operations.

A video of the TERRATEC TBM S79 breaking through on UG-01 in Pune, can be found here.

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