Coomera Connector South - Coomera, QLD

The Coomera Connector South (Stage 1) project is a critical infrastructure development in Coomera, Queensland. DGSA was engaged to provide specialised ground engineering support to facilitate the construction of a major retaining wall along a complex 300m stretch of the alignment.

To ensure long-term stability in highly compressible marine clays, we implemented a Mass Soil Mixing (MSM) strategy. This technique was selected to create a reinforced foundation block capable of supporting the significant lateral loads exerted on the retaining wall structure.

The project involves the comprehensive mixing of approximately 15,000 m³ of soil. The scope covers a treatment zone 10m wide and 300m long, extending to variable depths of up to 6m. The engineering objective is to achieve a target strength of 750 kPa at 28 days, ensuring a robust foundation for the infrastructure.

As this is an active, ongoing construction project, DGSA is currently working through technical challenges related to the variability of the marine clay deposits. We are managing this through continuous monitoring and adaptive mixing parameters to ensure consistent strength results across the entire 300m length.

The project is currently ongoing. Upon completion, the MSM-reinforced soil block will provide a stable, load-bearing foundation that mitigates the settlement risks typically associated with marine clay environments, directly supporting the structural integrity of the Coomera Connector.