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Re: Alternate design method

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Jim and Scott,
I graduated in 1962 when Ultimate Strength Design or Strength Design was one chapter or was in an Appendix of out text-books.
The so-called alternate method was the "method"
Gary

Jim Bessley wrote:
yes, an older version. None of my texts have an example. I have the "Notes" corresponding to that ACI code. It does not have an example using the alternate provisions. I'm guessing that if you go back far enough you go beyond the change to using the strength principles and changing load and phi factors then reducing the allowables. Jim

Up a bit late last night?

On 5/1/07, *Scott Maxwell* <smaxwell(--nospam--at)engin.umich.edu <mailto:smaxwell(--nospam--at)engin.umich.edu>> wrote:

    Jim,

    There is a chance an older version of PCA's Notes might have some
    examples
    of the use of the "Alternative Design Method", maybe including a wall
    example.  I used to have an older version, but I don't know where
    I have
    it at this point.

    My concrete text book does not.

    Regardless, since the "Alternative Design Method" bascially points you
    back to the Strength Design provisions in the code (i.e. Chapter
    10 and
    Chapter 14), you still more than likely need an example of
    Strength Design
    anyways...and there is a pretty good chance that PCA's Notes might
    have
    that.

    Regards,

    Scott
    Adrian, MI


    On Tue, 1 May 2007, Jim Bessley wrote:

    > Scott,
    > I understand all of that regarding your comments.  I would still
    like to
    > find an example.
    >
    > I do, however, appreciate your comments and thoughts on the matter.
    > Jim
    >
    > On 5/1/07, Scott Maxwell <smaxwell(--nospam--at)engin.umich.edu
    <mailto:smaxwell(--nospam--at)engin.umich.edu>> wrote:
    > >
    > > Jim,
    > >
    > > What code are you under?  Technically, under the current ACI
    318 (ACI
    > > 318-05...as well as 318-02), the "alternative method" (aka
    allowable
    > > stress design) is no longer permitted.  ACI 318 did leave a
    comment in the
    > > commentary that says that you may still use it, but the commentary
    > > technically has no force.  The exception is if you are doing
    some sort of
    > > environmental structure (i.e. tank), then you would use ACI
    350, which I
    > > believe still has the "alternative method" included.
    > >
    > > I would encourage you to use the main provisions in the code (
    i.e.
    > > strength design).  If you need examples to better understand those
    > > provisions, then you can get PCA's Notes on the use of ACI
    318.  I would
    > > assume that they would have an example of strength design of a
    wall with
    > > axial load and flexure.
    > >
    > > Regards,
    > >
    > > Scott
    > > Adrian, MI
    > >
    > >
    > > On Tue, 1 May 2007, Jim Bessley wrote:
    > >
    > > > Gary,
    > > > Sorry for the confusion.  Appendix A in the ACI 318-95
    Code.  Section
    > > > A.6(and the associated commentary
    > > > RA.6) states that compression members with or without
    flexure must be
    > > > proportioned using the strength design methods from chapter
    10 and that
    > > > capacities are to be taken as 40% of those from chapter
    10.  Section
    > > > A.2.1says load factors and reduction factors are to be taken
    as unity.
    > > >  I haven't
    > > > had to do a lot of wall design in concrete, and I don't have any
    > > references
    > > > or texts that provide an example for this situation with
    compression and
    > > > bending using the appendix.
    > > > Jim
    > > >
    > > > On 5/1/07, Gary Loomis <gloomis(--nospam--at)masterengineersinc.com
    <mailto:gloomis(--nospam--at)masterengineersinc.com>> wrote:
    > > > >
    > > > >  Old "alternate design method".  Do you mean working
    stress design?
    > > > >
    > > > >
    > > > >
    > > > > Gary W. Loomis, P.E., Senior Structural Engineering
    > > > >
    > > > > Master Engineers and Designers, Inc.
    > > > >
    > > > > -----Original Message-----
    > > > > *From:* Jim Bessley [mailto: jbessley(--nospam--at)gmail.com
    <mailto:jbessley(--nospam--at)gmail.com>]
    > > > > *Sent**:* Tuesday, May 01, 2007 4:45 PM
    > > > > *To:* seaint(--nospam--at)seaint.org <mailto:seaint(--nospam--at)seaint.org>
    > > > > *Subject:* Alternate design method
    > > > >
    > > > >
    > > > >
    > > > > I have to look at a wall section using the old "alternate
    design
    > > method"
    > > > > in concrete.  The wall section will have both lateral and
    axial
    > > loads.  It
    > > > > has been a very long time since I used this method, if
    ever.  does
    > > anybody
    > > > > out there have an example that I can get from you that
    will explain
    > > the
    > > > > process.  The "99 ACI code uses strength design with
    different phi and
    > > load
    > > > > factors, which have me confused.
    > > > >
    > > > > Any help would be appreciated.
    > > > > thanks,
    > > > > Jim B.
    > > > >
    > > >
    > >
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