# RE: Nail Slip

• To: <seaint(--nospam--at)seaint.org>
• Subject: RE: Nail Slip
• From: "Mike Valley" <mtv(--nospam--at)skilling.com>
• Date: Tue, 15 Aug 2000 20:52:58 -0700
```Nels:

The units noted in the code (for an empirical equation that "works")
require that the units on the coefficient be 1/ft, as follows:

delta = ... + coefficient x (L or h) x en + ...

delta is in inches
(L or h) is in ft
en is in inches

Therefore, for units to balance, coefficient must be in 1/ft.

All of this indicates that the code and your references are not in
error; they simply didn't fully document what is going on in the
empirical equation.

The derivation for the equations (including nail slip) is provided in
ATC 7.

-Mike

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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

-----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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