Read about Keller's design and construct soil improvement solution within metres of a major road servicing Sydney's CBD.

Project photo M4 East Westconnex

The project

As part of the broader M4 East WestConnex project, Keller was contracted to provide a design and construct ground improvement scheme for the widening of Wattle Street, a major RMS road servicing the CBD. Due to the presence of soft compressible material beneath the proposed road, ground improvement was required to reduce potential settlement of the pavement under future traffic loading.

The challenge

The treatment area involved working alongside, and around, several major below ground services, in addition to 24 hour live traffic, and all whilst working adjacent to environmentally sensitive parklands and watercourse.

The solution

The Keller design comprised the treatment of 24,000m3 using Mass Soil Mixing to depths up to 6.5m to improve the stiffness of the underlying soft clays. The treatment was successfully completed using our specialist mixing equipment comprising soil mixing tool and onsite grout batch plant. The technique provided our client with an improved area that could be used by other construction activities within three days of treatment, not possible with alternative ground improvement solutions.

Project facts


CPB Samsung and John Holland JV

Keller business unit(s)

Keller Australia

Main contractor(s)