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RE: Story shear for ramps; ramps as braces?

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My researching skills did not bring about a lot of results, meaning this is an issue that has not been addressed extensively
Is there any possibility that someone might have this paper for my reference.
What about the ramp? Seismic analysis and design of ramped parking structures
Lyons, Susan
Proceedings, 72nd Annual Convention, Structural Engineers Association of California , pp. 363-373. 2003
And my ELF analysis and ETABS results gave similar results (within 7-9%) when I assumed that half the ramp weight was transferred to the levels above and below. However, the top most story results were off by 25% with ETABS giving me higher values.
Any other information you can provide is very much appreciated. I work in the East Coast and seismic design is not an everyday occurence.


Kimberley Robinson <kimr(--nospam--at)> wrote:
This is an issue that is frequently overlooked.  You are right, the stiffness of the ramp is a problem in seismic design of ramped structures such as parking structures.  The best treatment I have seen on this topic is a paper written by the team at Watry Design, Inc. and printed in the PTI journal.  It is titled "Seismic Analysis and Design of Ramped Parking Structures" by John Purinton and several others, 2003.  Watry incorporates special detailing in their structures to ensure that the load is more likely to go where it is intended to go.
Buckling Restrained Braces, anyone?
Kimberley Robinson, PE

From: Rhkratzse(--nospam--at) [mailto:Rhkratzse(--nospam--at)]
Sent: Thursday, July 12, 2007 9:43 AM
To: anant_27(--nospam--at); seaint(--nospam--at)
Subject: Re: Story shear for ramps; ramps as braces?

Aside from the question Anantha is asking, I have always wondered how to avoid having the ramp itself be a very stiff diagonal brace to resist lateral (wind or earthquake) loads from story to story.  Assuming it's the stiffest structural element it would try to resist earthquake forces and, if unable to do so, fail.

Just curious; I don't design parking garages any more.


In a message dated 7/12/07 8:30:18 AM, anant_27(--nospam--at) writes:
I am designing a parking garage with ramps in both directions (dog-legged). How do I determine my diaphragm extents? Is it okay to take half the weight of the ramp to the story above and below to calculate story shears?

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