1.051 Structural Engineering Design
Prof. Oral Buyukozturk Fall 2003
1.051 Structural Engineering Design
QUIZ 2
Open Book & Notes โ 90 minutes
QUESTION 1. โ REINFORCED CONCRETE SHORT COLUMNS (30%)
A reinforced concrete short column with a square cross-section (22x22 in2) shown
in the figure below is reinforced with 4#11 rebars. The material properties are:
'4 ksi, 60 ksi, 29000 ksi
cy s
ff E
== =
22โโ 19โโ
3โโ
4#11
22โโ
shear stirrup
Figure 1
(a) How can you describe the failure behavior of this column under combined
axial load and bending moment effects for practical design? BRIEFLY
explain with the help of a sketch, indicating behavioral characteristics (No
calculations required)
(b) Compute the axial load capacity, (Po) of this column when a concentric load is
applied (e=0, M=0). Assume Ac=Ag.
(c) For balanced failure condition, determine the nominal axial load (Pb) and
bending moment (Mb), and the corresponding eccentricity (eb).
(d) Estimate, with a minimum of calculation, the nominal moment capacity, Mn, of
the column under the axial load of Pn=(Po+Pb)/2. (Reinforced concrete
analysis not required)
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