# RE: Snow load in combination with seismic

• To: seaint(--nospam--at)seaint.org
• Subject: RE: Snow load in combination with seismic
• From: <jwatson(--nospam--at)inconnect.com>
• Date: Thu, 07 Jun 2001 14:12:35 -0600
```In Utah we have adopted a statewide snow load study.  The equation for
snow included in seismic is:

% = (0.25+0.025*(Elevation-5000')/5000')

This is for Utah, Colorado may have a similar equation somewhere.

Jake Watson, E.I.T.
Salt Lake City, UT

-------------------
> Despite the fact that many engineers treat them deterministically,
> dependent on what happened in the past and on statistics.  Humans
are
> notoriously poor at predicting the future and even where rigorous
math
> is not used most people make decisions based on what seems likely to
> happen.  (Thus we don't carry eight spare tires in our cars.)
>
> If we based our designs on what is possible (given the past) rather
> than what is likely the design loads for all locations on earth
would
> be something like the following:
> human live load = density of people in the black hole of calcutta
> snow load = based on glacial cover during an ice age
> wind load = several hundred miles per hour for direct tornado
> volcano load = hundreds of feet of ash, mud; high thermal loads from
> lava
> electrical load = direct lightning strike
> earthquake load = perhaps M10 at ground zero
> etc.
>
> Once we decide to base loads on a specific service life or on a
level
> that is less than the maximum possible we should consider the
> statistics of the situation.  Once we decide that a given transient
> combining multiple transient loads, it makes sense for the
combination
> to have the same likelihood of occurrence as we previously accepted.
>
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
> Michael Valley, P.E., S.E.                   E-mail:
mtv(--nospam--at)skilling.com
> Skilling Ward Magnusson Barkshire Inc.
Tel:(206)292-1200
> 1301 Fifth Ave, #3200,  Seattle  WA 98101-2699      Fax:
-1201

*
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
*   send to the list is public domain and may be re-posted