Great Western Highway Upgrade, Bullaburra West
The Roads and Maritime Services (RMS) project involved the upgrade of a 2km section of the Great Western Highway from a two lane road to a four lane dual carriageway. Widening of the road corridor to allow the construction of the dual carriageway required the construction of 16m high reinforced earth (RE) walls on slopes of up to 30°, deep rock cuttings, stabilisation of active landslides and a 0.8m diameter underbore below the rail corridor for a stormwater pipe. All works were completed whilst maintaining the operation of the Great Western Highway with vertical cuts up to 15m deep excavated to the edge of the live road pavement. The global stability, sliding resistance and bearing capacity of the RE Walls were assessed in accordance with the RMS’s site specific specification (R57). The stability of finished rock cut slope was assessed in accordance with the RMS slope risk assessment guidelines.