Page 236 - Design of Reinforced Masonry Structures

DESIGN OF REINFORCED MASONRY BEAMS 4.99

The concentrated loads consist of 30 percent dead load and 70 percent live load.
Therefore, the unfactored loads on the end segments of the lintel are
D = 0.3 (2600) 780 lb/ft
L = 0.7 (2600) = 1820 lb/ft
The factored dead load (live load not considered in Load Combination 1) on the end
segment of the lintel is (Fig. E4.27E):
U = 1.4D = 1.4 (780) = 1092 lb/ft

1092 lb/ft 1092 lb/ft

1.31' 1.31'
3'

L e = 6'

FIGURE E4.27E

Calculate shears and moments due to combination 1 loads.
Due to triangular load on the lintel:
V = ½ W = ½ (983) = 492 lb
u
u
Due to distributed load on the end segments (Fig. E4.27F):
V = 1092 (1.31) = 1431 lb
u

1092 lb/ft 1092 lb/ft

1.31' 1.31'
L e = 6'
FIGURE E4.27F

Total factored shear = 492 + 1431 = 1923 lb
Moment due to the triangular load (W = 708 lb) on the lintel,
u
)( )
M = WL e = (983 6 = 983 lb-ft
u
u
6 6
Reaction due to distributed load on the end segments,
R = 1431 lb