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Re: Nail Slip

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Bill - Isn't only about a quarter of your wall's total deflection comes from
the holddown? Since about half comes from the plywood, you might try using a
higher G value in Table 23-2-J in the 97 UBC if applicable. Fred
----- Original Message -----
From: "Bill Allen" <Bill(--nospam--at)AllenDesigns.com>
To: <seaint(--nospam--at)seaint.org>
Sent: Thursday, August 17, 2000 6:57 AM
Subject: RE: Nail Slip


> John-
>
> Maybe when solving this equation by hand, the problem with the units is
not
> apparent, but it is when using something like Mathcad. This is why I had
to
> include a "12" in the denominator in the first and third terms in my
> example.
>
> More importantly, I invite attention to the results of the sample I posted
> on the web. Once again, see:
>
> http://www.allendesigns.com/sw/shearwalldeflections.htm
>
> If you notice, this is a fairly "normal" (i.e., moderately loaded) shear
> wall. Even though the aspect ratio meets Code (2:1), the deflection is
> (slightly) excessive (0.0266h vs. an allowable of 0.025h). This is mostly
> due to the use of a HD instead of a PHD or some other device which
minimizes
> hold down deflections.
>
> Imagine a highly loaded shear wall.
>
> Thanks,
>
> Bill Allen, S.E. (CA #2607)
> ALLEN DESIGNS
> Consulting Structural Engineers
> Laguna Niguel, CA
> http://www.AllenDesigns.com
> V (949) 365-5696
> F (949) 249-2297
>
> ||-----Original Message-----
> ||From: John Rose [mailto:jrose36(--nospam--at)earthlink.net]
> ||Sent: Wednesday, August 16, 2000 11:16 PM
> ||To: seaint(--nospam--at)seaint.org
> ||Subject: Re: Nail Slip
> ||
> ||
> ||Bill, it is dimensionally consistent. There are factors
> ||within the constants for
> ||each term that account for the apparent inconsistencies. Same
> ||applies to
> ||diaphragm deflection equation.
> ||John Rose/APA
> ||
> ||Bill Allen wrote:
> ||
> ||> Nels-
> ||>
> ||> As Dennis Wish once pointed out, this equation (along with
> ||others) is not
> ||> dimensionally consistent. I worked an example in Mathcad
> ||and converted it to
> ||> html. You can view this example at:
> ||>
> ||> http://www.allendesigns.com/sw/shearwalldeflections.htm
> ||>
> ||> I hope this helps in making this equation clearer.
> ||>
> ||> Regards,
> ||>
> ||> Bill Allen, S.E. (CA #2607)
> ||> ALLEN DESIGNS
> ||> Consulting Structural Engineers
> ||> Laguna Niguel, CA
> ||> http://www.AllenDesigns.com
> ||> V (949) 365-5696
> ||> F (949) 249-2297
> ||>
> ||> ||-----Original Message-----
> ||> ||From: Nels Roselund [mailto:n.roselund(--nospam--at)worldnet.att.net]
> ||> ||Sent: Tuesday, August 15, 2000 6:08 PM
> ||> ||To: seaint(--nospam--at)seaint.org
> ||> ||Subject: Re: Nail Slip
> ||> ||
> ||> ||
> ||> ||Mike,
> ||> ||
> ||> ||Thanks for pointing me to the answer.
> ||> ||
> ||> ||Your explanation [in the Archives], that the implied units of
> ||> ||the constant
> ||> ||in the nail-slip term of the equation is 1/ft, seems to make
> ||> ||sense.  It
> ||> ||gives the nail slip term a value of 1/12  of the result I got
> ||> ||by making the
> ||> ||Table value of en unit-less.  It also gives a result that
> ||makes the
> ||> ||contribution of nail-slip to the total deflection small
> ||> ||rather than the
> ||> ||major component of shear wall deflection.
> ||> ||
> ||> ||If the implied units of the constant were to be taken as
> ||> ||1/in, the result
> ||> ||would be the same as making en unit-less.
> ||> ||
> ||> ||Is your use of an implied value of 1/ft rather than 1/in based on
> ||> ||documentation, or on what you know of the derivation of
> ||the deflection
> ||> ||equation?  Or is your explanation based on what you, too,
> ||> ||found to give the
> ||> ||most sensible results?  I'd like to know that there is
> ||> ||documentation and how
> ||> ||to find it.  I don't like to have to  use magic formulas.
> ||> ||
> ||> ||Nels Roselund
> ||> ||Structural Engineer
> ||> ||
> ||> ||
> ||> ||-----Original Message-----
> ||> ||From: Mike Valley <mtv(--nospam--at)skilling.com>
> ||> ||To: seaint(--nospam--at)seaint.org <seaint(--nospam--at)seaint.org>
> ||> ||Cc: n.roselund(--nospam--at)worldnet.att.net <n.roselund(--nospam--at)worldnet.att.net>
> ||> ||Date: Tuesday, August 15, 2000 3:32 PM
> ||> ||Subject: RE: Nail Slip
> ||> ||
> ||> ||
> ||> ||>This was discussed on the list in July of 1999.  I
> ||posted on 7/8 and
> ||> ||>7/15.  The archives contain the info.
> ||> ||>
> ||> ||>- - - - - - - - - - - - - - - - - - - - - - - - - - - -
> ||- - - - - - -
> ||> ||>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
>
>
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