IPENZ: The Institution of Professional Engineers New Zealand (IPENZ) has today released an Engineering Snapshot – key points and lessons learnt from Monday’s 6.5 earthquake to help the public and building owners better prepare for the “big one”.
1. Damage is largely superficial with no significant structural damage.
2. Most modern buildings were flexible and moved with the tremors as they were designed.
3. Glass broke in older buildings because it was rigidly held in place. Practices have changed for new buildings.
4. Protection of critical buildings like Parliament worked because of base isolation systems, which use lead rubber bearings.
5. Concrete pieces that fell were cover or decorative and not structurally significant.
6. Car parks are flexible with ramps between levels that are designed to move, but they need to be checked to ensure the movement mechanism performed as designed.
7. Generally unreinforced masonry performed well – the quake was about 20-35 per cent of new building standards so masonry was tested but there is little sign of damage.
8. Interior fitting displacements – water tanks, pipes and ceiling tiles – occurred because of inadequate restraint. A standard for seismic restraint exists but it is voluntary and may need regulatory tightening. At present securings are often fitted as thought best by individual trades people.
Dr Cleland urged building owners to engage an engineer to check if systems worked and whether strengthening or repair work was required.
He urged engineers and building owners to act to reassure the public and help return confidence.