Sureway’s Role:
In 2018 Sureway was awarded the contract for the development of a new mine expansion area, Pit 09. Sureway completed the tree clearing for this expansion in 2017.
Work scope included reclamation salvage of topsoil and peat, drainage establishment including ditches, berms, and ponds, haul road construction, and original box cut development. The key challenge was the installation and backfill of 2 large diameter CSP primary water culverts through an environmentally sensitive ravine environment that had many complex geotechnical challenges (see next page). This is the largest 2000mm culvert installation and deepest buried of this type of culvert in Alberta.
Geotechnical Challenges & Construction Mitigation
Weak displaced soils at base of valley
- ZToeberm construction & aggregate buttresses installed
Borrow area –High Moisture Content
- ZSoil conditioning, selective backfill , achieved all compaction specs
Unexpected springs encountered
- ZConstructed French Drains
Valley slope movement due to Ancient failure-200m wide
- ZEmergency placement of buttress to slow movement
Slope stability of both sides of ravine
- ZRaised invert elevations 5m to avoid area
Slope stability—Ground movement
- ZExcavation, culvert installation & backfill completed in panels
Monitoring movement
- ZInstrumentation installed and raised during 30m of backfill depth
Backfill during winter conditions
- ZMaterial kept live from borrow– achieved all compaction specs
Project Statistics:
Location :
Highvale Mine, Seba Beach AB
Client :
SunHills Mining (TransAlta)
Our Services:
- ZSalvage of topsoil
- ZPond construction and drainage
- ZExcavation and Culvert
- ZHaul road and ditch construction
Scope of Work
- Z325,000 m3 - Topsoil stripping
- Z325,000 m3 - Topsoil stripping
- Z4.3 km - Ditches
- Z712 lm - 2000 mm diameter culvert—2 X 356m long
- Z4km - Haul Road Construction
- Z1,300,000 m3 - Original Boxcut excavation
- Z650,000 m3 - Ravine / culvert backfill—over 30m of culvert cover
- Z100,000 m3 - Unsuitable Ravine excavation
