2002 msjc code seminar notes

huangyhg

2002 msjc code seminar notes
i am trying to find where the 0.746 factor comes from when calculating the allowable stress fa for asd of unreinforced masonry bearing walls in the following example problems:
example 2a, page 6
example 2b, page 11
example 2c, page 15
i did look in the aci530/asce5-02/tms 402-02 building code requirements for masonry structure, page c-25 eq. (2-12) but didn't find anything.
thanks in advance for pointing me in the right direction.

additional question:
in example problem 2c, page 16, regarding the stability equation, the notes state "moments and axial forces from lateral loads are not included in this (stability) check."
why?  in a wall just on the verge of instablity couldn't lateral loads be enough to "push it over the edge"?
they are just showing you the math....
the first part of the term - 0.25f'm
the second part of the term - (1-(h/140r)^2) = 0.746
they separate the two to give you a feel for the effect of the slenderness on the total allowable stress.
jae,
now that you turned on the light switch, it seems trivial.  it seems that i looked at that for hours, i must have been in a trance.
thanks
well..honestly, i poured over it for some time looking for the damned 0.746 source as well.