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Re: UBC and Hurricanes - was FBC Standards

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Paul,
Puerto Rico.  Thanks for the reply. I learned a little
more to-day.  Still learning at 66.  Coming from an
earthquake deprived area, I have still have a lot to
learn.  Fortunately, I was able to find a US engineer
who helped me and refused any payment. He is a true
gentleman.
The new Canadian National Building Code is due out in
September and I hear it has now incorporated several
ideas in regard to EQ from your codes.
Regards
Gary

On 21 Jul 2005 at 13:14, Paul Feather wrote:

> Gary,
> 
> Where is your project?  The UBC has never been a strong code with
> regard to hurricane requirements.  The UBC has always been a primarily
> western states code, and hurricanes are simply not a factor here.
> 
> The few areas where I have used the UBC in a potential hurricane
> environment I have used ASCE 7 for wind requirements and added
> engineering judgment rather than rely on codified procedures in the
> UBC.
> 
> You specifically refer to soil conditions.  Poor soil conditions will
> have no effect on the hurricane requirements, but rather will really
> only effect the foundation design directly.  Seismic forces are
> created via relative motion imposed from the ground surface.  Poor
> soils or different types of soil response can have a tremendous impact
> on the magnitude, severity, and period of the ground motion which in
> turn can have a corresponding effect on the seismic forces generated
> in the structure.  Look at the recorded effect the deep alluvial soils
> had on the response during the Mexico City earthquake as an example;
> the earthquake motion traveled hundreds of miles and then changed up
> passing through the altered medium and caused severely amplified local
> ground motion, in many ways worse than the result at the actual
> epicenter.
> 
> Hurricane or wind effects in general are more dependent on the
> topography of the ground rather than the consistency.  Additionally
> hurricane forces are not cyclic in the same manner as seismic forces. 
> The forces may be really large, higher than seismic in some instances,
> but the manner and type of failure is radically different.  This is
> why the discontinuous zone increases are so important.
> 
> The current thread is focused on the FBC, or Florida Building Code,
> where I would certainly expect hurricane related provisions.
> 
> Paul Feather PE, SE
> www.SE-Solutions.net
> pfeather(--nospam--at)SE-Solutions.net
> ----- Original Message ----- 
> From: "Gary Hodgson & Associates" <ghodgson(--nospam--at)bellnet.ca>
> To: <seaint(--nospam--at)seaint.org>
> Sent: Thursday, July 21, 2005 4:35 AM
> Subject: RE: FBC Standards
> 
> 
> >A question abt the UBC from a Canuck who has never
> > had to use until recently.  The seismic requirements
> > impose a higher lateral force when soil conditions
> > are poor.  Shouldn't there be some type of increase
> > for hurricane type forces?  I know there is a danger
> > of liquifaction in seismic events, but there seem to
> > be more hurricanes and lots of damage.  Just a
> > thought.
> > Gary
> >
> > On 20 Jul 2005 at 6:54, John C. Jones wrote:
> >
> >> If that area gets a hit with a full force wind then it will really
> >> be nasty.  Ivan did tremendous damage, but I think the winds were
> >> only around 110 when it came ashore.  These storms seems to sit
> >> right off the coast at about 140 and then just drop like crazy as
> >> they hit that shallow water.  I'm mainly speaking to the MS/AL/NWFL
> >> shoreline.
> >>
> >> I was in a mandatory evac for Dennis while attending an ACEC
> >> meeting in Destin.  9 miles of travel in 2:15.  That was fun.
> >>
> >> John
> >>
> >>
> >> John Jones, PE, SE
> >> Board Certified Structural Engineer
> >> john(--nospam--at)struct-engr.com
> >> Barnett * Jones * Wilson, LLC
> >> Pell City & Tuscaloosa, Alabama
> >>
> >> -----Original Message-----
> >> From: Andrew Kester, P.E. [mailto:akester(--nospam--at)cfl.rr.com]
> >> Sent: Tuesday, July 19, 2005 8:42 PM
> >> To: seaint(--nospam--at)seaint.org
> >> Subject: FBC Standards
> >>
> >>
> >> After last year's canes that hit the FL panhandle, and after Dennis
> >> I am sure too, there was media discussion on how that area had
> >> lobbied hard to get the standards lowered when the FBC was being
> >> written. If you look at a current wind map in the FBC it does not
> >> make sense. Pay particular close to the Big Bend region, or the
> >> "arm-pit" on the Gulf side (only a geographic description), and
> >> there are wind contour lines that seem to bend a bit, and a big
> >> dashed line which means "EXCEPTION" to the wind-borne debris
> >> requirements. This area also has some coastal properties owned by
> >> Tallahassee politicians. Just my conspiracy theory.......
> >>
> >> The paper said those areas were literally paying the price for
> >> those lowered standards. It would be nice to see insurance
> >> companies lobby against the builders and politicians pushing
> >> through lower standards. It would be a smart investment on their
> >> part.
> >>
> >> Andrew Kester, PE
> >> Lake Mary, FL
> >>
> >>
> >
> >
> >
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> 
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