Client Challenge
The client in Tallai, Gold Coast faced a major landslip below their residence, which was undermining the house. They needed to underpin the building and stabilise the slip zone. After engaging a geotechnical engineer and obtaining a slope stability report, a careful assessment determined that rock armour would be the best solution to stabilise the slip zone and secure the existing dwelling.
Our Solution
We utilized locally quarried rock armour to address the landslip. 220 tonnes of revetment quarry rock was installed, along with geotextile fabric to prevent further soil erosion. The process involved carefully digging away the problematic slip until a solid foundation was established using excavators. This method required a meticulous and slow installation of 18 truckloads of rock to ensure the slip zone was fully stabilised.
Outcome
The entire area has now been stabilised, including the underpinning of the existing dwelling that was precariously situated above the slip zone. Since the completion of the project, the Gold Coast has experienced a couple of 1-in-100-year rain events, and the rock armour has successfully held the hill in place. The homeowners can now sleep well at night during heavy rains, knowing that the rock armour provides robust protection against water-induced movements.
Project Highlights
This project presented significant challenges due to difficult access and the vulnerability of the exposed slip. The dwelling was at risk of collapsing into the landslip zone as its footings had been completely exposed. Part of our work involved underpinning the existing dwelling's footings. Despite these challenges, the project was completed successfully within two weeks, providing a secure and stable environment for the residential property.
