Client: Seymour Whyte/UGL JV

Duration: 11 Months

Location: Green Square, NSW

This project involved major sheet piling and watering, digging a 20m-deep excavation for two stormwater tanks and pipe installation. Scope included management of contaminated land, piling, sinking, construction of two 8x20m caissons, and working around live services.

Effective groundwater management through careful risk assessment
Brefni completed water testing prior to the works to establish a water management plan. Sedimentation tanks were utilised on site for the water to be pumped into, tested, treated and disposed of. Proactive water testing allowed Brefni to plan for appropriate site conditions, minimising delays on site.

Through risk workshops with designers, subcontractors and the client, we planned and arranged for an innovative piling solution. This involved jacking precast concrete segments into the ground and excavating internal material as they went down. This reduced the inflow of groundwater, prevented over- excavation and mitigated ground settlement.

Processes to protect existing services during works
Brefni liaised with third-party utility contractors to locate, expose and protect the services during the works. Where required, temporary works designs were completed to support all services during excavation works. This ensured all works could be completed without delays and minimised the risk onsite.

Ensuring safe working in confined spaces
Due to the deep excavation and work within a 20m deep shaft, all construction methods and access/egress required appropriate confined spaces protocols. Brefni developed a project-specific rescue plan and utilised specialist plant for access and egress.