Central Interceptor

Comprehensive geotechnical and structural monitoring across 14.7km of tunnel works delivering real-time data to protect Auckland’s largest wastewater upgrade from groundwater, movement and stability risks.

Structural and Geotechnical Monitoring

The Central Interceptor project in Auckland, New Zealand, is a major initiative to improve the city’s wastewater system and reduce overflows into the harbours during heavy rainfall. It involves the construction of a 14.7-kilometer underground tunnel connecting the Western Isthmus to the Mangere Wastewater Treatment Plant.

The Challenges

Ghella Abergeldie Joint Venture has contracted Sixense to provide a monitoring solution for the project. The solution covers diverse needs such as groundwater monitoring, ground movement detection, and structural stability assessment at each shaft site and along the entire tunnel alignment.

To tackle saltwater intrusion challenges, boreholes were equipped with electrical conductivity meters to identify the source. To address flooding concerns, piezometers were installed alongside pumps. Text alerts were promptly sent whenever water levels rose in each pump, enabling timely response.

What we’ve delivered

Sixense provides a comprehensive solution for monitoring tunnel construction. A site-wide radio network, in conjunction with wireless self-powered dataloggers, has been implemented to facilitate reading the sensors. This solution allows for real-time data collection from geotechnical sensors across the site, ensuring both effectiveness and reliability while being cost-effective. Additionally, to monitor the vital infrastructure crossing multiple active motorway and rail lines, a Cyclop was the ideal solution for continuous monitoring.

All monitoring data collected from various instruments is automatically integrated into Sixense’s Geoscope software platform. By consolidating real-time monitoring capabilities into a single platform, Sixense effectively mitigates risks and empowers informed decision-making with readily available data