Naughton’s Gap Road suffered significant damage as a consequence of recurrent extreme rainfall events which triggered a 280 metre landslide. The extent of the damage prompted Richmond Valley Council (RVC) to close the road due to safety concerns and loss of road asset functionality.

Naughtons Gap Road provides a critical community function as the main connecting road between the townships of Casino, North Casino, and other key roads such as Bentley and Kyogle Roads in the north, leading to large townships such as Lismore.

Richmond Valley Council, in conjunction with Transport for NSW (TfNSW), took decisive action by formulating the initial eligibility concept. The project aimed to create a design adhering to current NSW disaster relief guidelines and deliver construction-ready specifications for required treatments. These treatments were designed to restore Naughtons Gap Road to its pre-disaster state and improve its design life capacity to deal with heavy rainfall events and suboptimal ground conditions.

The scope of works for the Naughtons Gap Road landslip included:

• Construction of a bored pile wall with 900 millimetre and 1050 millimetre diameter piles and 1550 millimetre wide by 650 millimetre deep capping beam, and reinstatement of downslope batter earthworks.
• Reinstatement of road safety barriers.
• Reinstatement of table drains and road and pavement drainage, including a slight realignment of the road to avoid partial property resumptions and minimise impacts from temporary construction works.
• Reinstatement of drainage culverts with additional pits and kerbed outlets to capture surface drainage via dish gutters for erosion prevention behind piled walls.
• Pavement reconstruction.
• Reinstatement of existing PUP services.

BG&E’s solution encompasses a comprehensive approach, integrating safety in design principles throughout the project’s lifecycle – including construction, operation, and maintenance phases.

Our methodology involves a study of design elements to proactively identify and address complete eligibility workplace health and safety considerations. Additionally, environmental sustainability, constructability, and operational maintenance aspects have been incorporated into our design framework.