In a statement to T&TI, a Snowy Hydro spokesperson said that during a recent blast in the transformer hall cavern, several segments were damaged and blasted material penetrated a temporary section of the main access tunnel (MAT) located directly below the cavern. The ‘breakthrough’ occurred between the transformer hall cavern and MAT one blast earlier than planned.
“This was a recognised risk associated with blasting in the area and appropriate safety measures were in place. This included bracing of the MAT concrete segments to ensure the tunnel is stable while excavation of the transformer hall cavern and the temporary section of the MAT is undertaken,” the spokesperson said.
There were no workers underground at the time of the blast, as per safety requirements.
Access beyond the affected section of the MAT remains closed until the breakthrough is completed.
Last week, in its latest project update, Snowy Hydro said the project’s three TBMs had tunnelled a total of approximately 9km and a surge shaft at Marica was now under construction.
