This piling project required us to work with 90 piles, each of which was 36 metres deep. We had 179 anchors that were 46 metres long each and the excavation of 34,000m³ was 10 metres below the water table. There were a lot of materials to work with!
The soil was found to contain acid sulphite. This was remediated and all hazardous, restricted and general solid waste was removed from the site. The construction side of the project required a walkway, stairs and a lift shaft to Wolli Creek Station.
The biggest challenge we faced was working beneath the water table, installing the rock anchors and dewatering the site. A dewater system was created to treat all water onsite before pumping it out. Despite the challenges, we finished on time, within budget and went above and beyond client expectations.
The second stage of this large project required us to construct retaining structures (a concrete in-situ wall) and conduct bulk excavation, detail excavation, anchoring and dewatering during works.
As the bulk excavation was carried out under the water table we shouldered the risk of general solid waste and any acid sulphate contamination; and because of our experience, the results were per our estimates.
10 weeks for demolition of basement car-park – a total of 790 car spaces for all stages.