A 200-metre crack has appeared in Hazelwood open cut’s southern mine wall, stretching diagonally across a burning stretch of coal batter.
A 100m exclusion zone has been set up around the crack site, after the rupture was discovered on Thursday, as geotechnical experts continue to assess the area for further signs of instability.
Deputy incident controller Alan Quinton said the crack was 2.5m wide and at some points 10m deep, however said it was not threatening any vital mine or power station infrastructure.
“At this stage the state is getting in experts to advise us of the implications of this crack, so we have withdrawn crews from that area as safety precaution,” Mr Quinton said yesterday.
The development has heightened concerns about the integrity of the mine’s northern batter, which runs adjacent to Princes Freeway, some 150m from the mine wall perimeter, where a separate fire is burning.
The same section of freeway was closed for seven months in 2011 after cracks appeared in the road surface after heavy localised rains.
However Mr Quinton said ongoing monitoring of the northern batter had shown no concerning signs of movement.
Vicroads has also been monitoring for signs of movement along the freeway since the enormous mine fires began on 9 February.