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					CONFIDENTIAL                                                               AP/OCT 2008/QSD133/103


                                                  yplp
                                                   V5

                                  UNIVERSITI TEKNOLOGI MARA
                                      FINAL EXAMINATION




      COURSE                            PRINCIPLES OF STRUCTURES
      COURSE CODE                    QSD133/103
      EXAMINATION                    OCTOBER 2008
      TIME                           3 HOURS




INSTRUCTIONS TO CANDIDATES

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

 2.          Answer four (4) questions 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:

                )   the Question Paper
                )   an Answer Booklet - provided by the Faculty
                )   a two (2) 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 7 printed pages
© Hak Cipta Universiti Teknologi MARA                                                CONFIDENTIAL
CONFIDENTIAL                                      2                 AP/OCT 2008/QSD133/103



QUESTION 1

a) Using suitable sketches explain how loads are transferred from the roof to the
   foundation.
                                                                        (10 marks)

b) Figure Q1b shows a simply supported beam with a cross-section 300mm x 600mm
   carrying 300mm thick brickwall.

    i) Calculate the ultimate design load to be resisted by the beam.
    ii) Calculate the reaction at the support due to the ultimate design load

          Given:
          The density of reinforced concrete          = 2400kg/m3
          The density of brickwall                    = 2200kg/m3




                                                                                    2.4m




                                                                                    0.6m

                        3.0m                               6.0m


                                         Figure Q1b


                                                                                   (15 marks)


QUESTION 2


a) Using suitable sketches explain how loads are transferred from one way slab and two
   way slab to the beam.
                                                                                 (8 marks)

b) Explain the behaviour of short column when loaded with:

    i)     Axial load
    ii)    Eccentric load
                                                                                    (7 marks)


 ) Hak Cipta Universiti Teknologi MARA                                          CONFIDENTIAL
CONFIDENTIAL                                         3               AP/OCT 2008/QSD133/103




c)   Determine the unknown reactions at the support, due to the loads carried by the
     cantilever beam as shown in Figure Q2c.


                                   5kN



                                         10kN/m             20kN/m


                         0.5m              1.5m             1.0m
                                  *-*-

                                           Figure Q2c
                                                                                  (10 marks)


QUESTION 3


a) Explain the following terms

     i) Resultant force
     ii) Centroid
                                                                                   (6 marks)

b) Figure Q3b shows a free body diagram of concurrent force system. Determine the
   magnitude and direction of the resultant force.


                                            y axis



                       150l\h«-                          xaxis

                                            45 u         100N



                                         200N

                                                Figure Q3b
                                                                                   (9 marks)




© Hak Cipta Universiti Teknologi MARA                                        CONFIDENTIAL
CONFIDENTIAL                                         4                       AP/OCT 2008/QSD133/103




c) Figure Q3c shows a precast concrete block 300mm thick. Determine the position of its
   centroid from point of reference P.




                                                                                               3m

         2.1m



                                        4.5 m                               4m


                                                 Figure Q3c

                                                                                            (10 marks)


QUESTION 4


a) The cantilever beam shown in figure Q4a is loaded with uniformly distributed load and
   point loads. Determine the support reaction and draw the shear force and bending
   moment diagram.

                                                                     5kN          3kN



                          1   <-
                                        10kN/m

                                            2.0m
                                                         ->
                                                              1.0m   i     1.0m


                                                 Figure Q4a

                                                                                             (8 marks)




© Hak Cipta Universiti Teknologi MARA                                                   CONFIDENTIAL
CONFIDENTIAL                                       5                  AP/OCT 2008/QSD133/103



b) For the beam shown in Figure Q4b, calculate the reaction at support A and B and draw
   the shear force and bending moment diagrams.




              5kN                                                                       10kN


                    f


                                     10 kN/m                20kN/m
                                                                                        ^
                                                                        11



                        2.0m            3.0m      1.0m      3.0m                 2.0m

                                 A                                           B
                                               Figure Q4b
                                                                                            (17 marks)




QUESTION 5



a) Figure Q5a shows the cross section of a timber beam. If the permissible bending stress
   of the timber is 10N/mm2, determine the maximum bending moment that the beam could
   safely carry.




                                                                   75mm x 150mm
                                                                   timber beam




                                          Figure Q5a
                                                                                            (6 marks)




© Hak Cipta Universiti Teknologi MARA                                              CONFIDENTIAL
CONFIDENTIAL                                          6                     AP/OCT 2008/QSD133/103



b) A short braced column in the situation of mild exposure is required to support an ultimate
   axial load of 2000kN.
     i) If the percentage of main steel reinforcement provided is 2%, calculate the size of
        square column required and choose the appropriate mild steel reinforcement when
        grade 30 concrete is used.
                                                                                          (14 marks)
     ii) Determine the height of the above column if it is classified as short column.
                                                                                             (5 marks)
             Given:
                 Equation 38 (a) BS8110
                 N =        0.4 feu (Ag - Asc) + 0.75 Asc fy




                                  Areas of round bar reinforcement (mm2)


    Diameter                            Number of bars
       (mm)           1        2        3      4          5      6      7      8      9
        20            314      628      942    1256       1570   1884   2198   2512   2826
        25            491      983      1474   1966       2457   2946   3439   3932   4423
        32            804      1608     2412   3216       4020   4824   5628   6432   7236
        40            1257     2513     3770   5027       6283   5740   8796   10053 11310




QUESTION 6


a) Explain the behaviour of the following beams when subjected to loading.

     i) Simply supported beam
     ii) Cantilever beam
                                                                                             (8 marks)

b) A 300 mm wide singly reinforced concrete beam is required to transmit an ultimate
   bending moment of 550kNm, inclusive its own weight. The beam is made of grade 30
   concrete and high yield reinforcement. Using the simplified stress block formulae given in
   BS8110 (parti),

     i) Determine the effective depth of the beam.
                                                                                             (5 marks)


© Hak Cipta Universiti Teknologi MARA                                                 CONFIDENTIAL
CONFIDENTIAL                                           7                       AP/OCT2008/QSD133/103



    ii) Determine the amount of steel reinforcement required.
                                                                                               (7 marks)

    iii) Choose the appropriate reinforcement for the beam and draw the cross-section of the
         beam.
                                                                                  (5 marks)
            Given:    For singly reinforced concrete,
                            K <      K' ,       K    = M/fcubd2
                                                K'   = 0.156
                                                z    = d [0.5 + V(0.25 - K/0.9)]
                                                z    < 0.95 d
                                                As   = M/0.87fy z




                                  Areas of round bar reinforcement (mm2)


    Diameter                             Number of bars
       (mm)           1        2         3      4          5      6      7       8      9
        6             28       57        85     113        142    170    198     226    255
        8             50       101       151    201        252    302    352     402    453
        10            79       157       236    314        393    471    550     628    707
        12            113      226       339    452        565    678    791     904    1017
        16            201      402       603    804        1005   1206   1407    1608   1809
        20            314      628       942    1256       1570   1884   2198    2512   2826
        25            491      983       1474   1966       2457   2946   3439    3932   4423
        32            804      1608      2412   3216       4020   4824   5628    6432   7236
        40            1257     2513      3770   5027       6283   5740   8796    10053 11310




                                        END OF QUESTION PAPER




© Hak Cipta Universiti Teknologi MARA                                                   CONFIDENTIAL