The challenge

• The Council's operational core: a $100 million-plus building opened in 2010, built to full modern code, housing 1,250+ staff and the civic chambers.
• After the February 2011 earthquake, the Council was forced to evacuate for several months while structural assessments were done.
• The repairs turned out to be minor and architectural. The evacuation was largely unnecessary, but with no measured record of the shaking, there was no defensible alternative.

What we did

• Ngāi Tahu Property installed a full CSI structural monitoring system.
• Sensor points throughout the building feed a central recorder.
• Shaking is analysed instantly against building-specific thresholds.
• A stay or evacuate status shows immediately to the building manager, with SMS and email alerts to the owner, manager and engineer.

The result

Through thousands of aftershocks and two M6 quakes in December 2011:

• Zero further evacuations.
• Instant stay or evacuate decisions, with clear “no action needed” and escalation criteria.
• Structural performance reports straight to the engineer.
• Maximum staff and public confidence, and uninterrupted city governance.

“Our primary concern is safety, and the system greatly assists in decision making related to the level of timing of repopulating the building. Of further benefit is that data on structural behaviour should contribute to future seismic design. The installed system also enables Christchurch City Council to immediately know the level of impact within the city’s Central Business District.”— Gordon Craig, Development Manager, Ngāi Tahu Property