With no water supply available on site, the drilling system was modified to minimise water usage, and an in-house designed grout mix was batched offsite and delivered via agitators, all while carefully programming activities to reduce the impact on local traffic congestion.
The project
To minimise the risk of future mine subsidence events beneath the proposed Newcastle inner city bypass, a portion of the future pavement area required mass grouting to remove the likelihood of voids or collapsible ground. Keller worked closely with the client and geotechnical consultant leading up to the works to develop the grouting campaign to practically and economically meet project requirements.
The challenge
The project involved substantial earthworks, plant movements and had limited water available on site. The traditional onsite grout batch plants were seen by the client as unfavourable due to space and logistics constraints on the wider project.
The solution
Keller successful produced and placed a custom fly ash grout using an offsite batch grout and delivered the grout in agitators. Grout was placed on multiple fronts to increase production and hand over completed zones to enable future works to commence. Regular downhole CCTV camera inspections were used to monitor grout flow and ensure it reached the target locations. All works were verified by the consulting engineer to meet SA NSW requirements.