# qsd133oct06

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```					CONFIDENTIAL                                                                      AP/OCT2006/QSD133

UNIVERSITI TEKNOLOGI MARA
FINAL EXAMINATION

COURSE                            PRINCIPLES OF STRUCTURES
COURSE CODE                       QSD133
EXAMINATION                       OCTOBER 2006
TIME                              2 HOURS

INSTRUCTIONS TO CANDIDATES

1.        This question paper consists of six (6) questions.

2.        Answer FOUR (4) questions only in the Answer Booklet. Start each answer on a new page.

3.          Do not bring any material into the examination room unless permission is given by the
invigilator.

4.           Please check to make sure that this examination pack consists of:

i)   the Question Paper
ii)   a one-page Appendix 1
Hi)    an Answer Booklet - provided by the Faculty
iv)    two sheets of graph paper - provided by the Faculty

DO NOT TURN THIS PAGE UNTIL YOU ARE TOLD TO DO SO
This examination paper consists of 6 printed pages
© Hak Cipta Universiti Teknologi MARA                                                 CONFIDENTIAL
CONFIDENTIAL                                                            AP/OCT 2006/QSD133

QUESTION 1

a) Explain the following terms:

i)     structure
iv)    force
(10 marks)

b) Figure Q1b shows a simply supported reinforced concrete beam size 400 mm x 800
mm. The beam is required to carry a 400mm thick solid clay brickwall throughout its
span, calculate:

i) the ultimate design load of the beam
ii) the reactions at support A and B.

Given:
The unit weight of reinforced concrete     = 25kN/m3
The unit weight of brickwall               = 23kN/m3

A

400mm thick brickwall                                  2.5m

A
400mm x 800mm reinforced concrete beam           v0.8m

B

t<
n

6m                         8m

Figure Q1b
-I
(15 marks)

© Hak Cipta Universiti Teknologi MARA                                         CONFIDENTIAL
CONFIDENTIAL                                                         AP/OCT 2006/QSD133

QUESTION 2

Based on Figure Q2a, Q2b, Q2c and Q2d, determine the reactions at each support.

50 kN

30 kN

Figure Q2a
(6 marks)

2.0m               10kN                 30kN
w
A
2.0m

w                     15kN

2.0m
v         20kN
A
1.5m
V

Figure Q2b
(6 marks)

© Hak Cipta Universiti Teknologi MAR A                                   CONFIDENTIAL
CONFIDENTIAL                                                                 AP/OCT2006/QSD133

15kN
^

1
1r

20kN/rr1                    35kN/m
1
fes
2m               2.5m                3m
<———> ^                  ^   ^                 ^

Figure Q2c
(7 marks)

SOkN
10kN

5kN/m

2m                 5m                     5m                2m

Figure Q2d
(6 marks)

QUESTION 3

a) Figure 3a shows the cross-section of a singly-reinforced concrete beam. Estimate the
maximum bending moment that the beam can carry.

10mm 0 top steel

500mm

32mm 0 tension steel

Figure 3a

© Hak Cipta Universiti Teknologi MARA                                                  CONFIDENTIAL
CONFIDENTIAL                                                          AP/OCT2006/QSD133

Given:
K' = 0.156
K = M/fcubd2
K < K' (singly reinforced)
z = d [0.5 + V(0.25 - K/0.9)]
z < 0.95 d
As = M/0.87fyz
Reinforcement - mild steel
Cover - 25 mm thick
(15 marks)

b) A timber beam spanning 4.5m is required to support a uniformly distributed load of 5
kN/m including its selfweight throughout the span. If the allowable bending stress of the
timber is 7 N/mm2, recommend the suitable size of the beam.
(10 marks)

QUESTION 4

a) Give the definitions of moment.
(5 marks)

b) Based on figure Q4b. Calculate the reactions at support A and B and draw the shear
force and bending moment diagrams.

10kN                                                   30kN

I                       20kN/m            10kN/m

2m                4m                3m             1m

Figure Q4b
(20 marks)

© Hak Cipta Universiti Teknologi MARA                                       CONFIDENTIAL
CONFIDENTIAL                                      6                    AP/OCT 2006/QSD133

QUESTION 5

A 300 mm wide singly reinforced concrete beam is required to transmit an ultimate bending
moment of 350kNm, inclusive of its own weight. The beam is composed of grade 35
concrete with high yield reinforcement. Using the simplified stress block formulae given in
BS 8110 Parti

i)     Determine the depth of beam required
ii)    Determine the amount of steel needed
iii)   Sketch the cross-section of the beam and show the dimension details of the bars.

(25marks)

QUESTION 6

A short braced column is required to support an ultimate axial load of SOOOkN using grade
35 concrete and mild steel reinforcement. Assume the percentage of main steel provided is
2%.

a) Calculate the size of the column if the cross-section is square and choose the
appropriate diameter of main reinforcement required.
(15 marks)

b) Sketch the cross-section of the columns in (a) and show the details of the reinforcement
bars chosen.
(5 marks)

c) Determine the maximum effective height of the column.
(5 marks)
Given:
Equation 38 (a)

N = 0.4 feu (Ag - Asc) + 0.75 Asc fy

END OF QUESTION PAPER

© Hak Cipta Universiti Teknologi MARA                                        CONFIDENTIAL
CONFIDENTIAL                                      APPENDIX 1                AP/OCT2006/QSD133

LIST OF FORMULAE

Reinforced concrete beam
K' * 0.156
K = M/!«bd*

For singly reinforced beam, K < K*

z < 0.95 d
A*

BS 8110 equation 38(n); N « 0.4f«, (Ag                + 0,75 AM&

Timber beam

z = bd*/6
Areas of round bar reinforcement <mm*J
Number    of     bars
Diameter          t

(mm)           1          2           3        4       §         \$     ?                0
————— ,L_
.

6       28        S7            85       113    142     170      108    22\$   255
8       50        101           151      201    282     302      362    402   453   I
10       70        157           236      314    393     471      §80    026   707
12       113       226           339      452    S85     878      791    904   1017
16       201       402           603      804    100S    1200     1407   1§00  1809
20       314       828           942      125S   1570    1884     2190   2&12 202©
25       491       983           1474     196\$   2467    2948     S439   3932 4423
32       804       1608          2412     321\$   4020    4S24     5828   6432 723S
40       1257      2513          3770     5027   6283    5740     8796   10053 11310

© Hak Cipta Universiti Teknologi MARA                                            CONFIDENTIAL

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