Overview//
< BACKWard was contracted to undertake basement civil works for the high-profile Crown Sydney development at Barangaroo South. The works involved bulk excavation and removal of 70,000m3 of heavily contaminated material. This was done through innovative ‘top-down’ methodology, whereby bulk and detailed excavation works were carried out underneath Lendlease’s high-rise construction. The site was remediated of asbestos, coal tar-impacted soils, restricted waste and other potentially hazardous waste materials.
Scope of Works//
- Demolition and removal of surface pavements
- Excavation and removal of asbestos contaminated soils in three stages: Stage 1 (15,000m3 in conventional open environment); Stage 2 (15,000m3 under the existing building, through penetrations cast into ground floor slab); and Stage 3 (40,000m3 under existing building as in Stage 2)
- Design and construct enclosed overhead gantry load-out system on ground floor
- Design and implementation of a containerised system for the safe removal of contaminated waste during Stages 2 & 3
- Design and construct dewatering system to lower the water table from RL1 to RL13
- Design, implementation and monitoring of ventilation system for Stages 2 & 3 when working under the building
- Design and construct 6,000m2 concrete blinding layer at each stage
- Detailed excavation of material from the core area and at sub-grade layer of the blinding concrete
- Full time environmental monitoring works and compliance with Environmental Protection Licences
