Mangoola Continued Operation Project
Overview:
Construction of a Techspan Precast Concrete Arch inclusive of the construction of reinforced earth headwalls, management of zoned material backfill, management of live traffic and over 20,000m3 of imported pavement materials, placement of on-site screeded materials, geotechnical testing and over 400,000m3 of site earthworks during backfilling.
Additionally the works included realignment of The Big Flat Creek involving the supply and installation of 360m of 3m diameter corrugated steel pipes in a triple cell configuration for the permanent diversion of the existing creek alignment.
Scope of work:
- Construction of Wybong Road Bypass including tie-in to the existing Wybong road
- Clearing and grubbing, including mulching of all vegetation
- Temporary erosion and sediment control for the duration of the works
- Replacement of unsuitable materials with select material
- Preliminary ground improvement works and bearing capacity testing
- Installation and backfill of the techspan arch system including the construction of the re-inforced earth walls
- Construction of mine haul roads and the re-build of the existing Wybong road to facilitate traffic through the newly constructed techspan arch underpass
- Installation of corrugated steel pipe culverts, including jointing
- Engineered fill embankments, including supply of select backfill materials
- Rehabilitation of disturbed areas following completion of works
- Erosion protection structures
Highlights and challenges:
- Management of groundwater and unsuitable materials during preliminary works
- Significant rainfall and severe weather throughout construction
- Management of live traffic interaction
- Complex lifts using dual cranes, staged backfill and working at heights
- Significant sediment controls to minimise the potential of erosion and water runoff into sensitive areas, and the associated impacts. It also allowed for management and monitoring techniques that ensure the controls are working efficiently
