I've been waiting for these. For anywhere else in the world, we should not expect much damage for an M6.3. However, the general statement is that the buildings were fine, but were exposed to 2g acceleration, which is almost a world record, and allows one to throw up hands.
As we look at the records, we see that nearly all of them have permanent displacements. This throws out the use of response spectrum methods. Engineers should not quote those spectral accelerations.
This is the most reasonable record, with minimal permanent displacement in the N-S direction (middle). I'm going with 80 cm/s with the cleanest velocity pulse yet. I'm using this one for analysis.
The displacement is a very minimal cycle, and demolishes all assumptions about response spectra and sinusoids. Nevertheless, the engineers will stick with tradition.
This can also be used as an input for explicit analysis. 20 cm of displacement is more like the centre of the Chile earthquake (M8.8). In fact, as I think about it, these records are almost exact duplicates of the max. Chile records. Remember that at the Chile epicentre, all modern soft-story buildings (cheap condos) collapsed, and were slated for the dump, farther out in Santiago at 40 cm/s. The integrated records showed 3m of permanent displacement at the epicentre.
I still believe that the 80 cm/s for Christchurch was amplified by a factor of 10. Really, we only expect 10-20 cm/s for an M6.3, and these small things rarely go super-shear.