Current through Register Vol. 63, No. 12, December 1, 2024
(1) Nonreinforced Masonry Walls. The limited
access zone for a masonry wall that is not reinforced and braced in accordance
with 437-003-0706(3)
must run the entire length of the wall, and
extend away from the wall a distance equal to the height of the wall plus four
feet.
(2) Limited Access Zone for
Masonry Walls. The limited access zone shall remain in place until the wall is
adequately supported to prevent overturning and to prevent collapse unless the
height of wall is over eight feet, in which case, the limited access zone shall
remain in place until the requirements of
437-003-0706(3)
of this section have been met.
(3) Bracing for Masonry Walls. All masonry
walls over eight feet in height must be adequately braced to prevent
overturning and collapse unless the wall is adequately supported. Bracing must
remain in place until permanent supporting elements of the structure are in
place. The bracing system must be designed by a registered professional
engineer, or follow the requirements of
437-003-0706(4).
(4) Protection of Employees On or Near Braced
Masonry Walls.
(a) A limited access zone must
be established when constructing a reinforced masonry wall.
(A) A limited access zone must be established
before construction of the wall begins.
(B) A limited access zone must run the entire
length of the wall, and extend away from the wall a distance equal to the
height of the grout pour plus four feet.
(C) A limited access zone must be located on
the side of the wall not scaffolded.
(D) All activity within the limited access
zone is under the direction and control of a competent person.
(E) Entry into the limited access zone is
limited to employees actively engaged in construction of the wall. No other
employees are allowed to enter the zone without permission from a competent
person.
(F) A competent person is
responsible for monitoring wind speeds. When speeds reach 25 mph all braces
must be examined and the site made secure.
(G) When wind speeds reach 35 mph, all
employees in the limited access zone and in proximity to the wall under
construction must move to a safe location.
(H) The limited access zone must remain in
place until any wall over 8 feet in height is adequately braced as per
paragraph 437-003-0706(4)(e)
of this section or supported to prevent
overturning and to prevent collapse.
(b) During construction of a masonry wall,
adequate bracing must be in place to prevent the wall from overturning or
collapse. If any of these conditions exist, the bracing is not needed:
(A) The wall is 8 feet or less in
height.
(B) A qualified person
demonstrates that modifications to paragraph
437-003-0706(4)(e)
are adequate when addressing these or other
inherently more stable conditions:
(ii) Infills in existing
walls;
(iii) Construction in
protected areas;
(iv) Changes in
wall thickness;
(v) Masonry
pilasters; or
(vi) Corner returns,
intersecting walls.
(C)
Permanent supporting elements of the structure are in place.
(c) Design bracing systems
according to paragraphs
437-003-0706(4)(d) and
(e) of this section and install them under
the direction of a competent person.
(d) A registered professional engineer must
design bracing when there is one or more of the following:
(A) The wall is more than 24 feet in
height;
(B) The minimum
requirements of 437-003-0706(4)(e)(A) or
(B) are not met;
(e) A structural masonry wall bracing system
must be designed by a qualified person. The design and installation of the
bracing system must comply with the following requirements:
(A) Minimum design requirements, including
minimum requirements per chapter 26 of the Uniform Building Code, for use in
Options 1 or 2:
Note: This information may be included in the
blueprints.
(i) F'm 1500 psi, concrete
block laid in running bond pattern.
(iii) 60 ksi rebar, with minimum placement of
2 - #4 horizontally and 1 - #5 vertically at 48 inches on center.
(iv) 2,000 psi grout required at reinforced
areas.
(v) Straight coil loop
insert with coil bolts (safe working load = 2250 lb.).
(vi) Metal concrete tilt braces.
(vii) Wall height not to exceed 24
feet.
(B) Minimum field
requirements for use in Options 1 or 2:
(i)
The horizontal spacing distance between two or more braces must not exceed 20
feet;
(ii) The horizontal bracing
distance from an end of wall or control joint must not exceed 10
feet;
(iii) A qualified person must
determine if walls less than 20 feet in length require two braces;
(iv) The connection of the brace to the
masonry wall must consist of a minimum 3/4 inch straight coil loop insert,
placed around a structural rebar located at an ungrouted bond beam;
(v) At least one structural rebar must be
located between the attached bar and face shell that receives brace (see figure
1);
(vi) The base connection of
brace must consist of a minimum 3/4 inch anchor attached to either a 4 inch
minimum thick slab or deadman;
(vii) The brace angle must not be greater
than 60 degrees from the horizontal;
(viii) The slab or deadman connection must
resist a minimum 3,400 lbs. pullout force.
(C) Option 1 -- Bracing structural masonry
walls when grout pours are limited to 5 feet 4 inches or less in height.
(i) A maximum 8 feet of initial wall height
may be laid with minimum reinforcement and then grouted.
(ii) A maximum 5 feet, 4 inches of additional
wall may be laid with reinforcement located to receive straight coil loop
inserts at the bond beam location.
(iii) The first brace must be connected to
the wall insert and attached to slab or deadman at base of wall.
(iv) The reinforced section must be
grouted.
(v) Additional wall may be
constructed following steps
437-003-0706(4)(e)(C)(ii) through
(iv).
(D) Option 2 -- Bracing structural masonry
walls with grout pours up to 8 feet in height.
(i) A maximum 8 feet of the initial wall
height may be laid with minimum reinforcement and then grouted.
(ii) A maximum 5 feet, 4 inches of additional
wall may be laid with reinforcement located to receive straight coil loop
inserts at a bond beam location.
(iii) Braces must be connected to coil loop
inserts in the wall and attached at the base to either a slab or
deadman.
(iv) The wall may be laid
and reinforced up to the grout pour.
(v) No more than 4 feet of ungrouted wall
above the brace point is permitted.
(vi) Grouting may be done after each section
of wall is adequately braced.
(vii)
A maximum of 8 feet of additional wall height may be constructed and braced
following steps 437-003-0706(4)(e)(D)(ii) through
(iv). Figure 1: [Figure not included, see ED.
NOTE.] Straight coil loop insert attached to rebar with perpendicular rebar
between it and face shell to receive brace.
Figure referenced is available from the
agency.
Stat. Auth.: ORS
654.025(2)
& 656.726(4).
Stats. Implemented: ORS
654.001 -
654.295.