Why Buildings Respond Differently to Earthquakes

[ricktee]

[/QUOTE]

PS: There is currently no call from us engineers to change the design per se. It is at this stage recommended to increase one safety factor out of several in the design; the one relating to the region in which a structure is to be erected.[/QUOTE]

Today's earthquake (13June11, magnitude 5.5) cause the collapse of another building in Christchurch. 3 major earthquakes in the last 10 months has cause substantial damage in Christchurch. I think it is logical to change the design of these buildings.

[Duncan74]

Wait for the report / investigation.

The building that collapsed today was a single storey building from what I can see, no idea how old or damaged it was in the earlier quakes. So if it wasn't meeting current regs then there's no logical reason to change the current regs.

There's been 3 big quakes in the lst 10 months. Does that mean there's more or less chance of another big quake? Where else in the world are there long term continuous Mag 5+ quakes. (Actually, the last 10 months makes no difference to the probaility of future unassociated quakes).

And if you change the code then that means that buildings will be a lot more expensive. You're already at the point of diominishing return with the regulations, as in a large increase in the additional cost of building due to a small increase in building strength. And that money isn't covered by insurance (as it would be betterment), so where would the money come from? You run the risk of requiring buildings to be so expensive that none get built and ChCh becomes abandoned.

[Duncan74]

Further to the above, then based on photo 21/29 from http://www.stuff.co.nz/5136864/Chris...thquakes-13-06 then the building that collapsed on Worcester / Stanmore was already fenced off, and it was the canopy that collapsed. Other partial collapses that have been reported have been of building being demolished where they were trying to dismantle to enable rebuilding.

[ralf-nz]

Today's earthquake (13June11, magnitude 5.5) cause the collapse of another building in Christchurch. 3 major earthquakes in the last 10 months has cause substantial damage in Christchurch. I think it is logical to change the design of these buildings.

What has changed due to today's earthquake? Have we any better/more/in greater detail information available now? I personally don't think so.

In addition one might say: Changing the design of NEW buildings does nothing to prevent OLD buildings from being affected. It would have helped nothing at all had there be change in the mean time.
The only remedy might be to evict all those people living and/or working in Christchurch region unless the buildings are proven as to comply with the current code - or even with 'your' new one.

Again this is a decision made by a society. What is acceptable - and what isn't?!