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RE: floods, hurricanes and earthquakes, nuclear power

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Thanks to everyone for links about earthquake in Japan.

Been interesting following events on twitter: Queensland floods, TC Yasi, NZ
earthquake, and Japanese earthquake. The way the population gets organised
and mobilised, and is ahead of the news, and the debates that ensue.
Wouldn't think could do much with 140 characters: but with links to blogs,
news channels, pictures. A great deal of information and mis-information
passed around.

Also interesting what gets more coverage. I think there was flooding and
landslides in Brazil with more deaths than during the Aussie Floods. But
that event was swamped by the flood of information about the Aussie floods.
Even locally some weren't happy that Queensland floods were leaving flooding
in Western Australia largely ignored: this being criticism of official news
channels.

Some issues raised on flood proofing of the housing. It seems a lot of the
traditional Queenslander houses which are on stilts, had been modified by
filling in the lower level and turning into extra rooms: defeating the
purpose.

Not heard much about buildings relative to TC Yasi. But estimates of
approaching winds were in excess of regional wind, and people were being
told to shelter in houses, others were evacuated but didn't have adequate
evacuation facilities and reports of people being turned away. Also
apparently the buildings weren't designed as post-disaster facilities. So
seems lucky that actual wind speeds were less than predicted.

No doubt, there will in ensuing months be calls for increasing design loads.
Personally I don't see the point in increasing design loads. No matter what
design load we choose the ultimate event is that it will be exceeded. We
still need the resources to deal with the disaster level event. It is not
that the building structures fail, but the manner in which they fail that is
important.

My simple example is. The Northen Territory is big on cyclone washers,
because during cyclone Tracy, large numbers of people were severely injured
by the sharp edges of steel roof cladding. The cyclone washers do not keep
the cladding on the roof, nor do they remove the sharp edges. The ultimate
event is the design load exceeded, and the roof cladding ripped free.

It seems we keep ignoring such. Everytime we mention hurricane resistant,
earthquake resistant, and flood proof buildings, the public starts believing
that they have protection from any level of event. Budgets to emergency
services are cut, and people become otherwise complacent about living in a
harsh and destructive environment.

A fine balance has to be achieved. Australia has had about 11 years of
drought, and then gets hit by flooding. Dams with dual purpose of water
storage and flood mitigation, were being used for storage: their ability to
mitigate a flood being reduced. We need to design better for these extremes.

Also most of our houses are timber framed to our timber framing code AS1684,
which is a pre-engineered solution. The ceiling diaphragm is just the
plasterboard ceiling. During the flooding people were evacuating to their
roof tops, but the houses were collapsing. During the rains ceilings were
also collapsing. See, in the main it doesn't rain, and so builders in
general not very good at weather proofing buildings: and the plaster board
not much use when it gets soaked.

BCA:2011 when it comes out early this year, will apparently have more
coverage for bushfires.

Not seen any official reports yet on the effects of flooding or TC Yasi on
structures.

Apparently these disasters worsen our shortage of engineers. Though there
always seems to be debates about migrant engineers having difficulties
getting jobs. So not sure where all this work is, that has the shortage.
Unless its a balance problem: one additional engineer no project, a 100
additional engineers then have a project. Engineers Australia's
infrastructure report card, identifying need for work, doesn't necessarily
mean there are any jobs to do that work, or money to finance the work. So I
have doubts the declared shortages are real and immediate.




Regards
Conrad Harrison
B.Tech (mfg & mech), MIIE, gradTIEAust
mailto:sch.tectonic(--nospam--at)bigpond.com
Adelaide
South Australia





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