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Re: Horizontal Irregularities

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I don't know. I want to say that it doesn't matter because ASCE says
"for connections of diaphragms to vertical elements and to collectors"
so as long as the direct connection can take the 25% increase that any
part of the internal diaphragm itself does not have to be increased.
It may be as simple as just increasing the number of direct
connections by 25% at the boundaries.  But it doesn't really seem 100%
right to me either.


Will



On Mon, Nov 3, 2008 at 4:58 PM, Doug Mayer <doug.mayer(--nospam--at)taylorteter.com> wrote:
> Grrr…I don't know why my responses to William's post are coming out garbled
> like that…sorry about the junk.  Anyway, one last time, here is my reply to
> William's last post:
>
>
>
> Agreed that the (possible) increased nailing requirement would only be along
> the boundary edge.  However, the way the code table reads is that to achieve
> the listed diaphragm capacity, the specified boundary AND edge nailing must
> be used.  It doesn't seem it would follow the intent of the table if you
> used 2.5" spacing only at the boundary edge and then immediately switched to
> 6" o.c. for all other edges after removing the 25% increase.
>
>
>
> Doug Mayer, SE
>
>
>
> From: Gerard Madden, SE [mailto:gmse4603(--nospam--at)gmail.com]
> Sent: Monday, November 03, 2008 11:42 AM
>
> To: seaint(--nospam--at)seaint.org
> Subject: Re: Horizontal Irregularities
>
>
>
> It applies to the boundary nailing in wood diaphragms, deck welds and shear
> studs to boundaries in metal deck w/ conc. etc...
>
> Where the diaphragm shear is not at a boundary (i.e. support in your
> diaphragm shear diagram) it does not apply per this wording.
>
> -gm
>
> On Mon, Nov 3, 2008 at 10:54 AM, Doug Mayer <doug.mayer(--nospam--at)taylorteter.com>
> wrote:
>
> Hmm, I worded that poorly.  Yes, the demand should be increased 25% per this
> section, but does it apply to the diaphragm shear values that you would then
> compare to the code allowable diaphragm shear?
>
>
>
> Doug Mayer, SE
>
> Structural Engineer
>
>
>
> TaylorTeter
>
> Partnership
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>
>
> 7535 North Palm Ave., Suite 201
>
> Fresno, CA 93711
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>
>
>
> From: David Topete [mailto:d.topete73(--nospam--at)gmail.com]
> Sent: Monday, November 03, 2008 10:46 AM
> To: seaint(--nospam--at)seaint.org
> Subject: Re: Horizontal Irregularities
>
>
>
> It appears the demand must be increased 25%, while the "allowable" shear
> values remain unchanged.
>
> On Mon, Nov 3, 2008 at 10:26 AM, Doug Mayer <doug.mayer(--nospam--at)taylorteter.com>
> wrote:
>
> Section 12.3.3.4 of the ASCE 7-05 states:
>
> "For structures assigned to Seismic Design Categories D, E, or F and having
> a horizontal structural irregularity…the design forces determined from
> Section 12.8.1 shall be increased 25 percent …"
>
>
>
> Does this requirement apply to diaphragm shear values taken from the code
> tables?  As I read it, it does not, but I would appreciate confirmation.
>
>
>
> TIA,
>
>
>
> Doug Mayer, SE
>
>
>
>
> --
> David Topete, SE
>
>
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