[CEUS-earthquake-hazards] no "right" answer

[Joe Tomasello]

Seth, et al:

This firm has been involved with recovery efforts of the tornado strikes of
February 5, 2006.  The tornado damage shown in the attached is perceived by
the locals to be the primary day to day threat from natural hazards.  

 

The failure mode is rather simple; the wind lifts the roof deck and buckles
the joists, which in turn pulls inwardly on the top of the precast panels
causing them to fall (see Image 647 and 307).  Evidence indicates that the
lateral force resistant system remained standing (see Image 313), however a
majority of the building collapsed. This design is pre-1997 NERHP, but
included seismic considerations. It's unlikely that additional seismic
resistance required by 1997 NERHP would affect the outcome. 

 

What I'm suggesting is that contrary to the accepted convention (more
seismic is better), we think there can be a case made that seismic design
does not cure all the ills created by the various different natural
disasters as advertised by FEMA.

 

Image 647 - shows failure mode

 

Image 313 - Shows seismic bracing

 

Image 307 - Shows failed panels large warehouse

  

 

 

-----Original Message-----
From: ceus-earthquake-hazards-bounces at geohazards.usgs.gov
[mailto:ceus-earthquake-hazards-bounces at geohazards.usgs.gov] On Behalf Of
Seth Stein
Sent: Wednesday, February 13, 2008 7:58 PM
To: WrightLa at usa.redcross.org
Cc: zmwang at email.uky.edu; ceus-earthquake-hazards at geohazards.usgs.gov;
cfostel at conwal.com
Subject: Re: [CEUS-earthquake-hazards] no "right" answer

 

 

Both are problems, but in the US severe weather kills about 500 people per
year and earthquakes kill about 10. Another way to look at this is that
every 6 years severe weather has the same net effect as the 1906 San
Francisco earthquake.

 

Seth Stein

William Deering Professor

Department of Earth and Planetary Sciences 1850 Campus Drive Northwestern
University, Evanston, IL 60208

(847) 491-5265 FAX: (847) 491-8060 E-MAIL: seth at earth.northwestern.edu
http://www.earth.northwestern.edu/people/seth

 

On Wed, 13 Feb 2008 WrightLa at usa.redcross.org wrote:

 

> When earthquakes don't happen, tornadoes are a bigger problem.

> 

> 

> 

> The recent loss of life due to tornadoes is horribly tragic, and not 

> to be belittled by any means, but the loss of life that could be 

> caused by an 1811 quake in the NMSZ beggars the imagination.

 

Joseph Tomasello, PE

5880 Ridge Bend Rd.

Memphis, TN 38120

 

Phone:

(901) 761-2016 office

(901) 821-4968 direct

(901) 412-8217 mobile

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