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Re: Sheilding

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>
>I have five identical buildings, spaced 16 feet apart.
>Building height
>is 120 feet. Building width is 60 feet - this is the dimension
>perpendicular to the wind direction. The dimension parallel
>to the wind
>direction is 20 feet. The buildings are in perfect alignment,
>such that
>the first one effectively shields the other four. 
>
>Normally, we would design one of the five buildings treated
>as a
>self-supporting entity subjected to full wind loading, then
>simply build
>five such structures, with or without interconnecting struts.
>The
>client, of course, understands the cost implications of this
>approach.
>
>This time, it's different - the client insists that we take
>advantage of
>wind load reduction due to shielding, and wants the five
>buildings to be
>interconnected and treated as one large structure.
>
>ASCE 7-95, paragraph 6.5.4, prohibits shielding, but the
>client
>guarantees that the five buildings will always stay together.
>If so,
>using shielding makes sense. A call to ASCE confirmed
>that paragraph
>6.5.4 is not gospel. Unfortunately, ASCE 7-95 does not
>address wind
>loading for series of buildings. Here are my questions:
>
>1. Is it OK to apply wind loads only on the windward wall of
>building 1
>and leeward wall of building 5?
>
>2. Is it reasonable to assume that, as the wind goes
>around the
>buildings, vacuum will develop in the spaces between the
>buildings,
>which in turn will generate suction on all interior wall
>surfaces? 
>
>3. If my above assumptions are incorrect, what would be
>the correct
>approach for applying wind loads?



i know this is late in the comments but here is my two cents
whether the code or not allows some type of reduction.. its a bad idea 
some engineers have said " don't do it unless you educate the owner" 
education or not your the professional its your responsibility

well some degree of education and verification by the owner 
may make you feel better.. but .. this building may stand beyond this owner..
he sells .. he disapears.. your screwed....  even if you win in some future
case..

there is no justification to design for shielding... i assure you that you
can never 
eleiminate long term liabilty....

Bill Lynch

BSD