Channel Brace Options
(Revised:
01/06/20)
This screen gives the ability
to define the use of Channel Braces (discrete bracing design) for Secondary
with any panel type. Channel Braces can be
used in roof surfaces as well as wall surfaces.
Rather than using the
prescriptive R-Factor of a covering achieved as a result of testing, secondary
design which may generate nested simple girts can be changed to use Channel
Braces so that single zee members discretely braced could be designed.
Change the “Option” column
from “System Generated” to “Must Use Channel Braces” to override R-Factor
design. The user can let the software
determine the optimum girt design and quantity of Channel Brace runs by leaving
the Hold Qty column set to System Generated, or override the quantity of
Channel Brace rows by using the drop down list.
Channel Braces in the wall
or roof can be controlled by Surface or per bay -
System
Generated = The software will decide if R-Factor or discrete bracing will be
used for design.
Some rules that
have been programmed:
1. If a jamb is within 18inches of a Channel
Brace location, the Channel Brace is not supplied and the jamb is considered to
act as the design brace point.
2. When changing the Channel Braces control
screen at the Default or Spaces level, one, two, three or four rows can be
selected but only those that fit or those allowed to be designed will be
detailed. i.e. Three is not allowed at
interior bays.
2. The user can specify up to 4 Channel Braces
in a bay, if only 2 Channel Braces will fit because of the secondary length,
then only 2 Channel Braces will be detailed regardless of the user input.
·
Channel Braces are only generated in bays wide enough for
the needed secondary punching; which is end bays of 14/2/0 or greater and
interior bays of 13/2/0 or greater.
·
With secondary spans greater than 33’ (DP 4.1) designing
with R values (i.e. SSR, PR, BRII, SLR II, VSR II) discrete bracing is
required. Typically adjusted by
engineering personnel.
3. The “most common” girt on the wall is punched
for the channel bracing. Of girts that
are not the same length as the “most common” girt, keyhole punching will not be
provided. Details (SED’s) are provided
for attaching the brace with self-drilling screws.
4. Girt Channel Braces are not generated in the
girt space between the floor and the first girt run unless there is only 1 run
of girts on the wall.
5. Face-to-face, back-to-back, face-to-back, and
structural members are not punched for the girt Channel Bracing. Girt Channel Bracing will generate and need
to be field attached with structural fasteners.
See also: