Masonry Magazine April 1992 Page. 30
LIMITATIONS ON CORBELING
P ≤ t/2
p ≤ h/2
p ≤ d/3
WHERE:
P = ALLOWABLE TOTAL HORIZONTAL PROJECTION
p = ALLOWABLE PROJECTION OF ONE UNIT
t = NOMINAL WALL THICKNESS
h = NOMINAL UNIT HEIGHT
d = NOMINAL BED DEPTH
Corbeling Limitations
FIG. 5
in masonry walls shall be embedded in reinforced bond beams or reinforced vertical cells.
A.3.7
Structural members framing into or supported by masonry columns shall be anchored thereto. Anchor bolts located in the tops of columns shall be set entirely within the reinforcing cage composed of column bars and lateral ties. A minimum of two #4 lateral ties shall be provided in the top 5 in. (127 mm) of the column. Welded or mechanical connections for reinforcing bars in tension shall develop 125 percent of the yield strength of the bars in tension.
A.3.8
Vertical reinforcement of at least 0.20 in.² (129 mm²) in cross-sectional area shall be provided continuously from support to support at each corner, at each side of each opening and at the ends of walls. Horizontal reinforcement not less than 0.20 in.² (129 mm²) in cross section area shall be provided: (1) at the bottom and top of wall openings and shall extend not less than 24 in. (610 mm) nor less than 40 bar diameters past the opening, (2) continuously at structurally connected roof and floor levels and at the top of walls, (3) at the bottom of the wall or in the top of the foundations when doweled to the wall, (4) at maximum spacing of 10 ft (3.1 m) unless uniformly distributed joint reinforcement is provided. Reinforcement at the top and bottom openings when used in determining the maximum spacing specified in Item No. (4) above shall be continuous in the wall." Minimum reinforcement requirements are shown in Fig. 6.
A.3.9
Where head joints in successive courses are horizontally offset less than one-quarter of the unit length, the minimum horizontal reinforcement shall be 0.0007 times the gross cross-sectional area of the wall. This reinforcement shall be satisfied with uniformly distributed joint reinforcement or with horizontal reinforcement spaced not over 4 ft (1.2 m) and fully embedded in grout or mortar."