Tarrawanna Slope Stabilisation
Slope stabilisation works at Tarrawanna, NSW, involving reinforced concrete footings, gabion rock bags, and rock mattresses to remediate landslip zones and protect residential properties. Works were delivered under constrained access and strict environmental controls.
Unicivil was engaged to support Aegis Consulting Engineers in the geotechnical remediation of two landslip zones within a residential complex in Tarrawanna, following flood events that triggered significant slope instability and bank erosion. These failures posed structural risks to adjacent dwellings, necessitating urgent and technically sound intervention.
Due to constrained site access, environmental sensitivities, and steep, geologically compromised terrain, a bespoke engineering solution was required. In close collaboration with Aegis, Unicivil developed and executed a tailored stabilisation strategy. Vegetation clearance and slope benching were undertaken to establish access to the embankment toe, facilitating the deployment of excavators and crane.
A reinforced concrete strip footing was installed to anchor gabion rock bags, which served as the foundation for ascending layers of rock-filled mattresses. This system provided mass and permeability, enhancing slope stability and erosion resistance. The integrated solution was designed to mitigate future landslip risk by enabling hydraulic permeability during high rainfall events, allowing water to filter through the gabion structure and discharge safely into the downstream creek. The reinforced toe formation offers resilience against elevated water levels, curbing further bank degradation and safeguarding the structural integrity of nearby properties.
Power in Numbers
2
60
120
Landslip Zones Remediated
Gabion Rock Bags Placed
M2 Rock Mattress Installed
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