Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Architects Doing Engineering -Enough!

[Subject Prev][Subject Next][Thread Prev][Thread Next]

Bill Allen, S.E. wrote:

No, this time I will offer a solution.
Bill Allen's solution certainly would result in in buildings which should perform better in an earthquake but it raise costs significantly.  Compare the cost of public school construction in California to that in other seismic states.  Is it worth doing?

That depends on what Bill is trying to achieve.  The Blue Book says that an acceptable outcome is "to safeguard against major structural failures and loss of life".  Do we want to change to a property protection code instead?  I doubt the insurance industry really cares.  All they need to due is assess risk, set premiums, fund reserves and wait.  After the "event" they simply hire a lot of lawyers to explain why we screwed up and they should not cover the loss.

Assume that SEAOC or others could achieve everything on Bill's list.  The damage and loss statistics that Fred Turner and others have cited still would not change significantly.  Why?  Because all the new code hoops that would be added would only apply to those buildings that have not yet been built.  Mandatory retrofitting existing structures would be necessary to significantly decrease losses and that is not on Bill's list.  If it were, it would be the hardest goal to achieve.  It seems that voluntary retrofits have caught on but perhaps that is just Darwin at work.

After reading all the posts on this issue, I have to agree with Frank Lew but perhaps for different reasons.  We tend to want to ratchet up the code whenever a large loss occurs.  As Frank has often said: "We just don't like people to die in groups".  We validate this action with photos of damaged buildings and heroic rescue attempts.  If you look at the damage carefully you will most likely find the buildings do not conform to the current code that we propose to change.  My experience tells me that we should expect reasonable  (i.e. Blue Book) performance from buildings that are both designed and constructed to comply with current codes, either engineered or conventional.   Remember that the conventional construction provisions just went through a significant tightening not in "design" but in application limitations. More may still need to be done but not to the level Bill Allen suggests.

Loma Prieta and Northridge have been mentioned.  I have taken some time to look at San Francisco - 1906.  Both federal and state government reports show that both unengineered wood buildings and UMBs performed well at Magnitude 8.3.  Damage was mostly confined to filled ground where soil failure occurred, usually soft story failures.  Even in those cases, numerous photos exist showing 3 story houses off their foundations but with not even any glass breakage.  Most UMBs were destroyed by burnout of the interior floors that laterally stabilized the walls.  The real culprit was fire from the reuse of earthquake damage chimneys.  It is interesting to note no major code changes resulted from this event and the unreinforced masonry construction was not outlawed until much latter.  In fact, seismic design was not required in California until the Reilly Act in 1933.

Bottom line, the engineering community needs to come to terms with the concept of risk  It can't be totally avoided.  We need to develop the best type of technical standards and make sure that the ultimate consumers of our services are well educated on their availability.  In a free society they get to make the choices.  Perhaps an additional $3,000 per house is not a good investment to protect from damage in a 100+ year event.  How much will it raise the bar that must be hurdled to qualify for a home loan?  Even if we required the $3,000 to be spent is earthquake safety the best place to do it.  Why not reduce highway fatalities or fire losses instead?

As far as public costs are concerned, who came up with the idea that government should use tax dollars to bail out disaster "victims"?  After 1906, San Francisco did just fine with its recovery  without such "assistance" but then there were less laws and, if I'm correct, no income tax.  How about encouraging self reliance rather than a victim mentality.

As far as stripping architects of engineering authority.  This would only result in the reciprocal stripping of engineers' ability to practice architecture.  Few architects practice engineering but most engineers practice a limited form of architecture, things as simple as specifying stair rise or run when designing a steel stair stringer.  Talk to some of our colleagues in the East where a rigid division exists between the professions and you will find engineers are prohibited from designing buildings used for human occupancy.  An architect must be the prime professional in responsible charge of the work.  An engineer may only serve as a sub-consultant.

All thing's considered,  I believe that Frank Lew's position is extremely realistic.

Just another point of view.

Bob Bossi