UFC 4-023-03
25 January 2005
a) the lesser of 2.0 Ft or (ls/2.5) Ft
(kN)
or
b) 3% of the largest factored vertical load, carried by the column or wall at
that level, due to conventional design load combinations
(kN)
where:
ls = the floor to floor height (m).
In English units, each external column and, if the peripheral tie is not located within the
wall, every 3.3 ft length of external wall carrying vertical load must be anchored or tied
horizontally into the structure at each floor and roof level with a tie with a required
tensile strength (in kips) equal to the greater of:
a) the lesser of 2.0 Ft or (ls/8.2) Ft
(kip)
or
b) 3% of the largest factored vertical load, carried by the column or wall at
that level, due to conventional design load combinations
(kip)
where:
ls = the floor to floor height (ft).
Where the peripheral tie is located within the wall, provide horizontal ties adequate to
anchor the internal ties to the peripheral ties.
Corner columns must be tied into the structure at each floor and roof level in
each of two directions, approximately at right angles, with ties having a required tensile
strength equal to the greater of a) or b) from the previous section.
7-2.7
Vertical Ties.
Tie each column and load-bearing wall continuously from the lowest to the
highest level. The tie must be capable of resisting a tensile force equal to the largest
factored vertical load received by the column or wall from any one story, due to
conventional design load combinations.
When a wall at its lowest level is supported by an element other than a
foundation, make a general check for structural integrity (i.e., make a careful check and
take appropriate action to insure that there is no inherent weakness of structural layout
and that adequate means exist to transmit the dead, live, and wind loads safely from the
highest supported level to the foundations).
Note that recent research and full scale tests on wood frame construction
conducted in the United Kingdom suggest that although the development of adequate
tie force capacity can be shown for wood frame construction, it may be more efficient to
show the bridging of deficient vertical load-bearing elements using the AP approach.
7-4
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