HW # 1

reelingripebeltUrban and Civil

Nov 15, 2013 (3 years and 9 months ago)

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HW #
1

ميحرلا نمحرلا الله مسب

Design of Concrete
Structure I

University of
Palestine

Instructor:

Eng. Mazen Alshorafa

Page
1

Design of Concrete
Structure I

University of
Palestine

HW #
1

w
D
=
2.0
t/m +wt of beam

w
L
=
2.3
t/m

6
m

60

54

30

3
Φ
30

Figure [
1
]

Problem

#

1

Figure

[
1
]

shows

a

simply

supported

beam

and

the

cross

section

at

midspan
.

The

beam

supports

a

uniform

service

dead

load

of

2
.
0
t/m

(excluding

own

weight

of

beam),

and

a

uniform

service

live

load

of

2
.
3
t/m
.

Use

f
c
’=
210
kg/cm
2

and

f
y
=
4200

kg/cm
2
.








1
-

Compute

the

factored

load

per

meter,

w
u
,

and

the

max
.

factored

moment,

M
u
.

2
-

compute

Φ
M
n

for

the

cross

section

shown
.

Is

the

beam

safe?




Page
2

Design of Concrete
Structure I

University of
Palestine

HW #
1

w
D
=
2.0
t/m +wt of beam

3.0
m

45

40

75

6
Φ
25

Figure [
2
]

P
L
=
5.0
ton

Problem

#

2

Figure

[
2
]

shows

a

cantilever

beam

and

the

cross

section

at

support
.

The

beam

supports

a

uniform

service

dead

load

of

1
.
5
t/m

(excluding

own

weight

of

beam),

and

a

concentrated

service

live

load

of

5
.
0
t

at

the

free

end
.

Use

f
c
’=
280
kg/cm
2

and

f
y
=
4200

kg/cm
2
.








1
-

Compute

the

max
.

factored

moment,

M
u
.

2
-

Compute

Φ
M
n

for

the

cross

section

shown
.

Is

the

beam

safe?



Page
3

Design of Concrete
Structure I

University of
Palestine

HW #
1

2.5

7.0

6.0

5.5

Figure [
3
]

Problem

#

3

Select

reinforcement

for

a

7
m

span

rectangular

beam

with

b=
40
cm,

and

h=
55
cm
.

The

beam

supports

its

own

weight

plus

a

superimposed

service

uniform

dead

load

of

1
.
0
t/m

and

a

uniform

live

load

of

3
.
0
t/m
.

Use

f
c
’=
350
kg/cm
2

and

f
y
=
4200

kg/cm
2
.


Problem

#

4

Select

reinforcement

for

a

rectangular

beam

with

b=
80
cm,

and

h=
30
cm
.

The

beam

supports

service

dead

load

moment

of

8
t
.
m

and

a

live

load

moment

of

6
t
.
m
.

Use

f
c
’=
250
kg/cm
2

and

f
y
=
4200

kg/cm
2
.


Problem

#

5

What

is

the

minimum

depth

required

for

the

continuous

beam

in

figure[
3
]

to

control

deflection

?



Page
4

Design of Concrete
Structure I

University of
Palestine

HW #
1

Figure [
4
]

Problem

#

6

The

beam

shown

in

Figure

[
4
]

carries

a

uniform

service

dead

load

of

3
.
0
t/m

(including

own

weight

of

beam),

and

a

uniform

service

live

load

of

1
.
2
t/m
.

Use

f
c
’=
210
kg/cm
2

and

f
y
=
4200

kg/cm
2
.

[three

possible

loading

cases

are

shown

in

figure
.






1
-

Draw

factored

bending

moment

diagram

for

the

three

loading

cases

shown

and

superimpose

them

to

draw

a

bending

moment

envelope
.


2
-

Design

the

beam,

selecting

b,

d,

and

reinforcing

bars
.


3
-

Draw

an

elevation

of

the

beam

showing

that

the

reinforcement
.


4
-

Draw

cross

section

at

the

points

of

maximum

positive

and

negative

moment
.


w
D
=
3.0
t/m

w
L
=
1.2
t/m

w
D
=
3.0
t/m

w
L
=
1.2
t/m

w
L
=
1.2
t/m

w
D
=
3.0
t/m

7.0
m

2.7
m