1

Problems:

1. Determine the ultimate moment capacity,

fMn, of a beam with dimensions b = 14 in.,

deffective = 17.5 in., and h = 20 in., and that has three No. 10 bars (3.81 in.2) of tension-

reinforcing steel. Fy = 60 ksi, and f’c = 4 ksi.

Answer:

fMn = 258.9 k-ft

2. For the beam of Problem 1 which is simply supported and 32 ft long, and where the loads

are dead load = 320 lb/ft (not including self weight) and live load = 185 lb/ft, determine if

the beam is adequate in bending. = 150 lb/ft3.

Answer: yes (Mu = 131.8 k-ft)

3. For the beam of Problem 1, check whether the amount of tension steel is within the limits

for ductile beam behavior. (Refer to the table for maximum

in Note Set 10.1)

Partial Answer: yes (As-max = 4.43 in.2)

4. For the beam of Problem 1 and 2, calculate the shear capacity,

vVc, and determine if the

beam will required stirrups.

Partial Answer: yes (Vmax >

2

cvV

= 11.6 k)

5. A reinforced concrete column in a rigid frame has a design compression load of

Pu = 170 kips, and a design moment of Mu = 34 k-ft. With the interaction diagram

provided on the next page, determine the amount of reinforcement (number and size of

bars) required for a 10 in. square column.

Partial Answer: more than 4-#7.

6. A two story, three bay portal frame has lateral loads from wind at each story as shown. All

columns are W12 x 40’s while all beams are W 18 x 55’s. Using a computer-based structural

analysis program, determine the shear, bending moment and axial load in each member (V, M

& P). Identify the column and beam with the critical design values. Submit the model file

(.mfd) on E-learning, and provide a print of the diagrams.

Partial Answers: Vmax (2nd windward column, 1st story) = 31.35 kN

Vmax (1st windward beam, 1st story) = 11.10 kN

Pmax (1st windward column, 1st story) = 14.89 kN

Pmax (1st windward beam, 1st story) = 54.19 kN

Mmax (2nd windward column, 1st story) = 75.76 kN-m

Mmax (1st windward beam, 1st story) = 60.43 kN-m

75 kN

40 kN

10 m

10 m

10 m

4.5 m

4.5 m

W18x55

W 12x40

2

7. Is the ultimate tensile capacity of 2-#6 grade 40 reinforcing bars greater than that of 1-#8

grade 60 bar?

Partial Answer: 2-#6 T = 35.2 kips, 1-#8 T = 47.4 kips

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amitae

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Address:
Architecture

University:
Bengal Engineering & Science University

Subject:
Architectural Structures

Upload date:
22/12/2012