Transcript الشريحة 1 - جامعة فلسطين

Design of Concrete
Structure I
‫بسم هللا الرحمن الرحيم‬
HW # 2
Instructor:
Eng. Mazen Alshorafa
University of
Palestine
Design of Concrete
Structure I
University of
Palestine
HW # 2
Problem # 1
Compute ΦMn for the beams shown in figures [1] and [2].
Use fc’=300kg/cm2 and fy=4200 kg/cm2.
120
15
15
120
55
55
6Φ20
6Φ25
30
30
Figure [1]
Figure [2]
Page 1
Design of Concrete
Structure I
University of
Palestine
HW # 2
Problem # 2
For the beam shown in figure [3], Use fc’=300kg/cm2 and fy=4200 kg/cm2.
1- Compute the effective flange width at midspan.
2- Compute ΦMn for positive and negative moment regions Note that the bottom
reinforcement is not adequately anchored in the support to serve as compression
reinforcement at the face of support. Therefore, it can be ignored.
0.15
3.3m
3.3m
0.60
7Φ22
In one layer
0.30
6Φ22 in 2 layer
6.30
Figure [3]
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Design of Concrete
Structure I
University of
Palestine
HW # 2
Problem # 3
The beam shown in Figure [4] carries a uniform service dead load of 3.0t/m
(including own weight of beam), and a uniform service live load of 1.2t/m. Use
fc’=250kg/cm2 and fy=4200 kg/cm2. [three possible loading cases are shown in figure.
wL=1.2 t/m
wL=1.2 t/m
wD=3.0 t/m
7.0 m
wD=3.0 t/m
wD=3.0 t/m
wL=1.2 t/m
2.7 m
60
15
100
Figure [4]
30
1- Draw factored bending moment diagram for the three loading cases shown and
superimpose them to draw a bending moment envelope.
2- Select reinforcement at the negative and positive moment regions
Page 3
Design of Concrete
Structure I
University of
Palestine
HW # 2
Problem # 4
For the beams with double reinforcement shown in Figures [5]and [6], Calculate the
design moment Md. Use fc’ =250 kg/cm2 and fy = 4200 kg/cm2.
6.3
6.5
3Φ25
2Φ25
56 65
51 60
6Φ25
6Φ25
27.5
27.5
Figure [5]
Figure [6]
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