Snowy 2.0 monitors surface depression above tunnel

Snowy Hydro says the integrity of the tunnel at Tantangara has not been compromised, and tunnelling is continuing while work to remediate the surface depression above TBM Florence is carried out. There is a safety exclusion zone around the depression.

The Snowy Hydro and main contractor Future Generation Joint Venture are conducting geophysical investigations and continuing grouting operations and probing from the TBM.

The ground conditions encountered by Snowy 2.0’s TBMs have been highly variable, ranging from very loose, sandy ground to extremely hard rock in fluctuating groundwater conditions.

TBM Florence, the third and final TBM for the project, was launched in March and is now transitioning from soft material into harder rock conditions.

In October Australian media reported that TBM Florence became stuck earlier this year after meeting variable and soft ground conditions. At the time, Snowy Hydro said the TBM had resumed excavating following successful reinforcement works.

“As anticipated, the ground conditions encountered by the TBMs on Snowy 2.0 have been highly variable, ranging from soft, sandy ground to extremely hard rock. The Snowy 2.0 teams have been working collaboratively to safely navigate the softer ground conditions experienced at Tantangara, including high groundwater inflows,” the organisation said in a statement on its website in October.

“As part of the tunnelling process we probed in advance of the TBM, identifying the soft ground ahead, and then consulted with our expert design consultants to plan for stabilisation works. TBM Florence has been specifically designed to encounter these variable ground conditions.”

Snowy 2.0, Australia’s largest renewable energy project, was in the news this week after Webuild, part of Future Generation, announced it was buying the assets and certain projects from its joint venture partner Clough Group, which went into voluntary administration on December 5. Webuild’s purchase includes Clough’s share of the Snowy 2.0 and Inland Rail contracts, and the option to buy other projects.

In a statement on its website yesterday, Snowy Hydro said it welcomed Webuild’s move to buy Clough’s share of Snowy 2.0 and its related workforce.

“Our priority remains ensuring the well-being and continuity of Clough’s workers on the project and the smooth progress of Snowy 2.0 construction. We will continue to work closely with Webuild and the administrators throughout the acquisition process,” the statement said.