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RE: Hundreds Of Calif. Hospitals At Risk Of Collapse

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So the buildings have been serviceable for 39 years. What is the point of
retrofitting them, and misleading the people into believing the buildings
are safe? Codes are crazy: stronger doesn't make it safer. Start with person
getting crushed by 1 ton concrete panel, get paranoid, make stronger, next
big event several people get crushed by 10 ton concrete panel. Sure made it
safer.

The acceptable load is a matter of subjective opinion, dreamed up by the
code writers: a matter of fiction. What ever it is, there is always the
probability that it can be exceeded. When it is exceeded then life is in
danger. It is how the structure behaves and responds to the load, and how it
collapses and what hazard it creates after the collapse that is more
important. More sensible than running around tell everyone we can stop the
building from collapsing. The buildings are going to collapse: full stop:
nothing we can do about it.

The owners expend the money on retrofitting, and the next big event exceeds
the design load: the hospitals collapse any way. But now no money to replace
the hospitals.

Seems like a more sensible risk analysis needs to be conducted than simply
upgrade all the hospitals. Our task is largely to maximise the benefit
obtained from the available but otherwise limited resources. We cannot keep
using more and more resources to construct a single building.

Take the Chinese earthquake, if had Mongolian yurts rather than concrete
apartment blocks, then a few people may have got tangled up and suffocated,
but few would have been crushed or buried, and recovery would have also been
much more rapid. Damage to the materials would not have been permanent: that
is structures may have collapsed: but stand them back up again after the
event.

It is not just a matter of whether we can survive the environmental hazard,
but how quickly we can recover after the event, and how we respond during.
How do people get to the hospital? And how do supplies get to the hospital?
And the housing has that all been upgraded? How certain can we be that all
systems in a region will fail at the same event and no sooner, and as
expected? That is all houses have collapsed and all post-disaster facilities
remain fully operational: and the region can recover on its own with out
external assistance.

Codes seem to be based on a vague notion, and there is no code which
defines a rigorous assessment of what should or should not go into a code.
Take the Australian codes: they are semi-probabilistic. But there is no
clear separation between the hazard to life, the loss of amenity and the
economic loss. A building can be maintained and remain operational beyond
its expected economic life. If not operational the building may still remain
in the environment. Rural and industrial buildings in particular. Rural
buildings tend to have lower design loads because in remote areas. Secondly
houses and other normal importance buildings are not expected to provide
shelter from extreme environmental hazards: nor remain serviceable after
such events. The primary objective is to minimise injury resulting from
ultimate failure: the deemed-to-satisfy provisions of the code achieve this
be adopting high loads with a low probability of being exceeded. Alternative
approaches are permitted as long as the fundamental performance criteria are
met: which at its simplest is that the structure be sufficient for purpose. 

Those willing to can step outside the structural codes because they are not
mandatory, only deemed-to-satisfy: and so seek more innovation solutions on
condition they can provide adequate evidence-of-suitability. That is they
can adopt an approach using the risk management standards, which are not
called up by the Building Code of Australia (BCA): and thus present and
demonstrate suitability of what the BCA calls an alternate-solution.

I therefore would take it that if the hospitals are reviewed on a case by
case basis, then after 39 years, some of the buildings are close to the end
of their economic life. And if US TV shows are anything to go by, then some
hospitals have more immediate building and other issues to resolve: than
whether the building will survive some possible future earthquake. For
example larger hospital with more medical staff required. Heritage can be a
benefit and an hindrance. 

Industry can find spare land overseas to build a new hi-tech factory. It can
then demolish original factory and build a still more efficient factory. So
that at any point in time have one factory operating and another being
constructed or fitted-out.

But a hospital generally cannot be relocated. So once got a hospital
generally stuck with it. That poses a problem for sustaining its operation
in the long term. Manufacturing wise maximum efficiency is typically
achieved if only operate at 90% of capacity: the remaining capacity is part
in planned maintenance or in reserve as emergency stand by. If don't do this
can have a high risk of losing significantly greater proportion of capacity.
Bean counters don't like this however, they want to operate at 100% capacity
and beyond to push growth. But growth seldom adequate to justify expansion
of facilities: so tend to operate overloaded on the brink of disaster. 

Hospitals are no different. If hospitals have spare beds, then no
justification for building new hospitals. New hospitals only built, when
excess demand is considered to be permanent. Profitable industry it may be,
but profits don't measure whether it is an effective, sustainable and
quality service provider.

The buildings and other infrastructure we have, our heritage, are taken for
granted. We can build upon our heritage but it is not always suitable
foundation for the future. Its like solving Rubics cube: have to mess it up
to move forward. We have disasters because we fail to accept a more
evolutionary short term inconvenience. It is also like the example of the
frog. Throw into scolding water and it will immediately jump out, put it in
warm water and slowly bring to the boil and the frog will stay there and
boil to death. Humans are the same: they become complacent.

Fatigue is an accumulate phenomenon. So building survives one or more
earthquakes or hurricanes, building looks perfectly fine and people start to
assume can occupy the building safely during and extreme event: but the next
event is minor and reaches the fatigue limit of the material and disaster
ensues: and everyone is wondering why.

I believe it is better to accept that nature is all powerful, and its forces
are far too great and impractical for us to resist: most especially as
individuals. Better to learn to flow and ride with the forces, than to
resist. I mean, there is a 2 metre wide crack in the ground outside: but no
worries the building will stitch the ground together: I doubt. Ok! Most of
the time it is just vibration.  But that's the point, its just vibration,
the building resists, so no worries, and become complacent: and not prepared
for the aftermath of failure event.

By increasing the resistance, we displace the failure event to some more
distant future date: we do not eliminate the failure event. In doing so
failure is not perceived as an eventuality, and preparation for is
neglected.

Can have a perfectly sterile environment and live in such, but the
introduction of a minor bug and the population can be wiped out. By having
less than sterile, have the potential to develop own resistance external
bugs which may ultimately invade.

In similar manner it is the individuals ability to respond to the hazard
which matters, not the resistance of the buildings. If already in a hospital
at time of an extreme event then already at a disadvantage. At the ultimate
event the hospital will fail, and the hospitalised are dependent on others
to get them out, and those injured are dependent on how quickly field
hospitals can be setup, and where such can be set up. The design event is an
inconvenience, the ultimate event exceeds the design event and becomes a
disaster if individuals and emergency services are not able to respond
appropriately.

The optimum solution therefore is a balance between our ability to respond
and provide services and recover from destructive forces versus our ability
to resist those destructive forces. Optimum solutions are typically only
valid at a given point in time and for a small range of variation. A quality
robust solution is valid over a much greater range of variability.

I believe our current approach is displaced from optimum and not quality
robust, and is far too biased towards resisting the great forces of nature.
On top of which the public face of engineering, tends to con the public into
believing we can resist those forces. Like the medical scientists, one week
something is good for us, the next it causes cancer, the next week its good
again: basically they have no idea and appalling knowledge of statistics:
but it fills a news slot arguing one way and then the other. Likewise
whether or not our buildings can resist earthquakes.

The last destructive earthquake Adelaide experienced was in 1954, so
apparently we don't have earthquakes nor hurricanes or other storms:
builders tell me so regularly. The last earth tremor I experienced here in
Adelaide, was about a week after the Chilean earthquake, prior to that
around the early 1980's. Whilst storm damage occurs to buildings at around
90km/hr to 110km/hr every year, yet regional design wind speed is 162km/hr.
Cyclone Larry demonstrated that older buildings pose a risk to new
buildings. We could go to the expense of upgrading all existing buildings,
on the other hand they are our heritage, they have survived thus far. So do
we really need to be constructing newer buildings for greater load
conditions? Besides the BCA is revised each and every year: so that would be
a programme of continuous upgrade to meet current codes. Revision generally
clarifying meaning and intent: which implies some approved buildings have
not met the objectives. Which suggests that maybe go modify last years
buildings, not quite meeting the objectives, to meet the clarification in
this years code. Keep people in the building industry employed at any rate.
Short of work raise panic, all for the good of public safety. But really
it's a con, no one is improving public safety, just increasing the
resistance and cost of the structure. And the cost of future reconstruction:
and ignoring money, it simply means more resources required to provide less
amenity. For example materials that could have provided two hospitals now
can only provide one hospital, when we need four hospitals. Not exactly
maximising the benefit from the available but otherwise limited resources:
which is fundamentally the role of engineering. Scarce resources how can we
best use them? Just about any technician can size the beams to the code: but
are there any real engineers with the imagination and ingenuity to go beyond
the self-imposed constraints of the codes and solve the real problems rather
than apply the known solutions?

Put simply when the hospitals have been upgraded and strengthened: the
hospitals will be at risk of collapse. The risk maybe lower, but it is still
there. So what is the point? Accept the risk you have and prepare to respond
accordingly to the failure event not some arbitrary design event. After all,
lucky the failure event has not occurred already, and need to be lucky it
does not occur before the upgrade is complete, and then need to be lucky
that the design load is not exceeded too soon after the upgrade. That is a
lot of luck to try and hide behind science.



Regards

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





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