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Re: '97 UBC Design - Are you too old to change your ways???

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Chris has made some very astute observations here (see below), and all
should read them and think a little about what he has said.

I do indeed agree that the costs to society due to earthquakes, major
floods, hurricanes, ice storms, tsunamis, and  all other acts of nature
effecting our designed structures are "too high".  Unfortunately, the
definition of "too high" is not an engineering term, it is a political
one.   I have never felt that society has given us engineers the mandate
to go forward with a stringient performance-based structural building
code applied to all structures universally.  Until they do, we are
perhaps well out of scope from our mandate (with the likes of UBC97,
IBC2000, etc), which is to protect the public safety.

I am, however, a stong proponent of advancing the state of practice
towards achieving reliable performance levels higher than life safety. 
Of first priorities of course would be applications to infrastructure and
structures housing critical occupancies.  The old "I" factor was just too
crude to be of much assurance in that regard, and a rational (and
understandable) methodology endorsed by the code process would have its
place.  Beyond those critical structures, and until society says
otherwise, it will remain the individual owner's prerogative to request a
higher level of performance.

So what happens when the owner requests a higher performance level? 
First, we have the simple yet profound problem of terminology.  There are
no universally accepted definitions for performance beyond life safety. 
That will be a critical first step, but an absolutely necessary one.  I
have devised an accepted language, but it is tailored to the aerospace
industry.  The US military have another set of largely inappropriate
definitions., as does the nuclear power industry.    

So lets say we jump that hurdle, and devise and accept definitions for
multiple performance levels for each of the various classes of structures
(residential, commercial, industrial, health care, etc).  Then we devise
and adopt some sort of design methodology for these structures, adaptable
to all structure types and materials.  Then we boldly advise our clients
of these new and wondrous techniques, and some of them even commission us
to design them.   What then of the costs to society from earthquakes? 
What effect do you think we will have?  Could we have averted the $15-20B
in residential losses in 1994.      NOT!!!     

We still have not addressed all the residential losses not atributable to
structural deficiencies.  Gas leaks, water leaks, cracked foundation
slabs, sliding of sub-foundation soils, leaky roofing, ruined furniture,
cracked swimming pools, landscaping, finish cabinetry, etc, etc, will
still happen, and losses will still occur.  We have to be realistic as to
just how much of that $20B is really ours, and whether we can really
offer our clients the omnibus protection they may  want and need. 

To provide a really meaningfull protection against all seismic hazards
and losses, we would have to be prepared to advise clients concerning
these ather types of losses and provide at least some kind of guidance in
thier achieving this additional protection.  So we could choose to
provide a limited service in regard to seismic loss protection
(primarlily structural), and clearly advise our clients as to these
limitations.  We could even advise as to the additional services and
steps needed to achieve total protection.  Or we could (individually)
choose to expand our services into the "seismic engineering" realm, and
provide all those other services for those clients who feel the need for
them.

What we should not do, in good conscience, is continue to force all
structure owners to build and buy ever stronger structures when the
economic value of these enhancements may have far exceeded their costs.  
We may be (and my opinion is that we are indeed) chasing ever diminishing
returns.

(Jeez, did I go off big this time........must have got too much sleep
last night.  Sorry for the rant again, but I find these discussions to be
loooong overdue.  I'll try to calm down again and go to bed.)

Russ Nester
rnester(--nospam--at)juno.com
_____________________________________________________________________
On Fri, 24 Sep 1999 01:10:32 -0700 "Chris D. Poland"
<cpoland(--nospam--at)pacbell.net> writes:
>This is a multi-part message in MIME format.
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>To all who were thoughtful enough to write and to all who are 
>listening:
>
>Pleae read my messsage again.  I does not suggest that the 97 UBC is 
>the
>answer to the Northridge problem.  It only argues that earthquake 
>engineering
>is an emerging technolgy, that the cost of Northridge damage is said 
>to be
>unaccepably high, that it is largely due to residential construction, 
>and
>that we need to embrace change.
>
>If you have ever heard me speak, you know that I agree whole heartedly 
>that
>we, as structural engineers, are doing our job. Our modern buildings,
>designed and constructed properly are performing in a life safe 
>manner. BUT,
>that is not the issue.  The issue is that the cost to fully restore 
>our
>communities is too high. Many people think that all we have to do is 
>make the
>structural code tougher.  But we (the designers) all know that only 
>solves
>part of the problem. The other part, the most expensive part, we do 
>not deal
>with and neither does anybody else. That is where the change is 
>needed, and
>we need to take the lead.  Nobody else knows what to do but us.  We 
>need to
>make a clear statement about what we are doing, publically state that 
>our
>designs do not prevent very costly non-structural damage and then 
>listen to
>the public about what they really need.  I think we are in for a 
>surprise.
>
>Do you realize that most people think that the stingent structural 
>provisions
>of the code are going to prevent major loss in the next earthquake?  
>Do you
>know that the UBC does not clearly dispute this expectation?
>
>Chris Poland
>
>ps:  Check the roster of the code writers.  You will find a lot of 
>practicing
>structural engineeers who care enough to volunteer.

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