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Re: Re: retaining snow loads

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Rich,
In the California Sierras, there are areas which often have 60' of annual
snow fall.  During these winters there are is usually about 20 to 25 feet of
snow on the ground near the end of the season and about 15 to 20' on the
roofs that don't shed.  Here is how we deal with allot of snow in this area.

How in the world do you snow plow it?  --- after each storm, then use large
blowers to clear the side of the roads.

Do you have these huge walls of snow 40 - 60 feet high on the side of the
road?  --- yes but not that tall.

Do you shovel your roof clean after every snow, which must be every day for
that big of snow fall? --- No, that is what engineering is for.

 What do you do with 100 feet of snow melt in the spring? --- the 25' of
snow does not melt quick enough to cause problems.  (except for the flood of
(I think) 1996)

  How does a ski lift adjust for 100 feet of snow?   --- again +ACI-only+ACI- about
25'.  The towers are usually tall enough, but in some locations they use
snow cats to push the snow away for clearance below the chairs.  The top and
bottom stations are adjustable for height.

Getting back to the original topic, I have seen snow cause the damage as
described by others on this list, but I do not think that it is analogous to
active pressure.  Not only is a vertical cut in the snow stable it actually
shrinks back.  Lateral pressure is caused by snow continually sliding into a
gap, filling the space between the existing pile of snow and the wall, or by
the impact force of the ice bouncing into the wall.  A similar siutation to
active pressure is snow creep.  Large amounts of snow on a slope can creep
down hill and it exerts a tremendous amount of force.  I have heard reports
of lift towers failing in shear due to this.

Randy Vogelgesang S.E.
South Lake Tahoe

-----Original Message-----
From: Richard Lewis +ADw-rlewis+AEA-techteam.org+AD4-
To: seaint+AEA-seaint.org +ADw-seaint+AEA-seaint.org+AD4-
Date: Friday, September 17, 1999 2:13 PM
Subject: Re: Re: retaining snow loads


+AD4-Bill,
+AD4-
+AD4-I don't doubt your word on this.  If you say it is 100 feet a year, and
+AD4-confirm the 100 feet, then I believe you.  But being originally from PA,
and
+AD4-now in TX, I just can't fathom how you could survive in 100 feet of snow.
+AD4-Do you ride in gondolas 150 feet up?
+AD4-
+AD4-Rich
+AD4-
+AD4-
+AD4-seaint+AEA-seaint.org writes:
+AD4-We had a failure of a ski area structure in Alaska due to lateral loading
of
+AD4-snow that slid off the roof.  Do not know if the design engineer wrote
+AD4-anything about it. The structure is located at Alyeska Ski Resort, near
+AD4-Anchorage.  Snow fall exceeds 100 feet per season.How in the world do you
snow plow it?  Do you have these huge walls of snow
+AD4-40 - 60 feet high on the side of the road?  Do you shovel your roof clean
+AD4-after every snow, which must be every day for that big of snow fall?  What
do
+AD4-you do with 100 feet of snow melt in the spring?  How does a ski lift
adjust
+AD4-for 100 feet of snow?
+AD4-
+AD4-Seems prudent to consider lateral loads from roof fallen snow.
+AD4-
+AD4-Bill Scott, P.E.
+AD4-VECO Engineering
+AD4-949 East 36th Street, Suite 500
+AD4-Anchorage, AK 99508
+AD4-
+AD4AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBf-
+AD4-
+AD4-Richard Lewis, P.E.
+AD4-Missionary TECH Team
+AD4-rlewis+AEA-techteam.org
+AD4-