Page 346 - Design of Reinforced Masonry Structures

5.66 CHAPTER FIVE

of the applied load, calculate the total service load, dead load, and live load that
can be supported by the column.
5.5 A 16- × 16-in. brick masonry column has an effective height of 18 ft. It is rein-
forced with four No. 7 Grade 60 bars. Assume ′ f = 2500 psi. Determine fP for
m n
this column.
5.6 A nominal 16 × 24 in. CMU column having an effective height of 24 ft is rein-
forced with four No. 9 Grade 60 bars. It carries a service dead load of 100 kips
and a service live load of 250 kips. ′ f = 1800 psi. Determine fP for the column
m n
and check if the column can support the imposed service loads.
Problems for design
5.7 Design a 24- × 24-in. CMU column to carry a service dead load of 250 kips
and a service live load of 250 kips. The effective height of the column is 24 ft.
′ f = 1800 psi, f = 60 ksi.
m y
5.8 Design a square CMU column to carry a service dead load of 200 kips and a
live load of 250 kips. The effective height of the column is 16 ft. ′ f = 1500 psi,
m
f = 60 ksi. Assume initially area of longitudinal reinforcement as 2 percent of
y
the net cross-sectional area of masonry.
5.9 Design a 16- × 24-in. CMU column to carry a service dead load of 200 kips and
a live load of 250 kips. The effective height of the column is 16 ft. ′ f = 1800 psi,
m
f = 60 ksi.
y
5.10 Design an 18 × 18 in. brick masonry column to carry a service dead load of
175 kips and a live load of 225 kips. The effective height of the column is 16 ft.
′ f = 1800 psi, f = 60 ksi.
m y
5.11 Design a square brick masonry column to carry a service dead load of 150 kips
and a live load of 250 kips. The effective height of the column is 16 ft. ′ f = 2500 psi,
m
f = 60 ksi. Assume initial area of longitudinal reinforcement as 2 percent of the net
y
cross-sectional area of masonry.
5.12 A nominal 16- × 24-in. CMU column is reinforced with four No. 9 Grade 60 bars
as shown in Fig. P5.12. The effective height of the column is 20 ft. The service
dead and live loads are 150 and 200 kips, respectively. Assuming ′ f = 2500 psi,
m
calculate the moment-carrying capacity of the column about its minor axis
(axis parallel to the long side of the column).
5"
15
8

5"
23 h = 20'
8

4#9
FIGURE P5.12