Black Mountain Road Landslide, QLD

The rain event in early 2022 had severe impacts across Noosa Shire and resulted in extensive damage to roads, water crossings, and stormwater outlets.

The Black Mountain Road landslide is the biggest landslide on the Sunshine Coast in 30 years. Geotechnical assessments after the landslip determined much of the damage was below the surface, measuring as wide as a rugby league playing field and as deep as a five-storey building. Coming up with solutions to restore the area has been complex and involved extensive geotechnical and engineering investigations.

Hazell Bros commenced work on the reconstruction in October 2023. The works will stabilise the road with depths between 5m to 25m across the 130m span and improve subsurface drainage.

Works completed to date:

  • Removed and reinstated landslide embankment (largest landslide in the Sunshine Coast in the last 30 years)
    • Excavated and disposed of ~2284m3 landslide unsuitable material
    • Placed ~1300t of 300-500mm rock
    • Placed and compacted ~675m3 select/general fill in landslide embankment
  • Additional geotechnical boreholes

Scope for 2024:

  • Excavate and dispose of ~3000m3 of existing road box/embankment
  • 60no. x 30m long horizontal drilled drains
  • 266no. 900 diameter bored piles (23-28m deep)
  • ~4,400m3 of reinforced concrete
  • 67no. x 35m long Ischebeck Titan self-drilling soil anchors
  • Construct pile caps and road tie beams ~1,670m3 of reinforced concrete