ROYS RD INTERCHANGE, SUNSHINE COAST
The Roys Road Interchange near Caboolture, South East Queensland, was an $88 million dollar project involving construction of a 2-lane overpass, exit and entry ramps, a local road connection, new pavement, resurfacing of local roads, and roadside revegetation.
Revegetation of roadsides is an important final step in road construction. In Queensland, works on public roads need to follow the Main Roads Technical Specification (MRTS) 16 Landscape and Revegetation Works.
For this project, SESL Australia prepared the soil assessment report for revegetation works including recommendations to improve the soil to meet the specification where possible.
Due to the presence of Wallum Frog on the site, the naturally acidic nature of the soil meant that it did not comply with the specification. The soil report, therefore, had to detail areas of non-compliance with justification as to why this non-compliance would not threaten the re-vegetation works. A compromise was sought where minor amounts of lime would be used to neutralize the excessive aluminium in the soil, but not raise the pH high enough to affect the frogs.
Soil samples were analysed at SESL’s laboratory to the MRTS specification 16B forms C (topsoil) and D (subsoil).