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OCD016

UNIVERSITY OF BOLTON

RAK ACADEMIC CENTRE

BENG (HONS) CIVIL ENGINEERING

SEMESTER ONE EXAMINATION 2017/2018

ADVANCED STRUCTURAL ANALYSIS AND DESIGN

MODULE NO: CIE6001

Date: Tuesday 10th January 2018 Time: 10.00am to 1.00pm INSTRUCTIONS TO CANDIDATES: There are FIVE questions on this

paper. Answer ALL questions.

All questions carry equal marks. Marks for parts of questions are

shown in the brackets. This examination paper carries a

total of 100 marks. All working must be shown. A

numerical solution to a question obtained by programming an electronic calculator will not be accepted.

Extracts from EC3 for use in Question 1 are attached on Pages 9-10 of this paper.

of 10 University of Bolton RAK Academic Centre BEng (Hons) Civil Engineering Semester One Examination 2017/2018 Advanced Structural Analysis and Design Module No. CIE6001

Question 1

(a) Compare the structural behaviour between stocky and slender columns and analyse the imperfections that affect the buckling behaviour of slender columns.

(4 marks)

(b) Figure Q1(a) shows a pin ended real strut made of steel strip 20mm x 3 mm having a length equal to 100 mm. The strut has a small initial curvature causing a departure of y0 = 0.5mm at its mid length. If an axial load of 5KN is applied to the strut compute the average stress in the strut.

Figure Q1(a)

(6marks)

Question 1 continued over the page…

E = 205KN/mm2

fy = 275 N/mm2


Question 1 continued…

(c) A multi-storey building requires an internal steel column which will carry an ultimate design axial compressive load of 1500 kN. The column has pinned boundary conditions at each end, and the inter-storey height is 6 m.

Determine the buckling resistance of column about both the axis by using EC3 method, if the option proposed is to use a Hot rolled UKC 203x203x60 Class 1 section as shown in Figure Q1(b) in Page 3.

(10marks)

Figure Q1(b)

Total 20 marks Question 2 The L shaped bracket shown in Figures Q2 (a) and Q2(b) is connected to a steel column 303.4mm deep with 6No M20 grade 8.8 bolts. The shear capacity of one bolt is 91.9kN and the tensile capacity of one bolt is 110kN. The bracket is formed from UB305 x 165 x 40kg/m steel section with the following properties: Web thickness 6 mm Flange thickness 10.2mm Depth of section 303.4mm Width of section 165mm A factored vertical load 70 kN is applied at Point A at the location shown in the plan view of the bracket.

(a) What is the out of plane moment in the bolt group? (2marks)

(b) What is the in plane moment in the bolt group?

(2marks)

(c) What are the tension and the shear forces in the hardest working bolts? (16 marks)

Question 2 continued over the page…

E= 210x103N/mm2



Figure Q2 (a)

PLAN VIEW ON BRACKET

Figure Q2 (b) SECTIONAL ELEVATION A-A ON BOLTED ENDPLATE

SHOWING SETTING OUT OF BOLTS Total 20 marks

Please turn the page

90mm

90mm

70mm

70mm

73.4mm

660mm 90mm

600mm

303.4mm


Question 3

Figure Q3a Figure Q3a shows the section of a composite steel/concrete beam. The E value of the steel is 205 kN/mm2 and the E value of the concrete is 13.3 kN/mm2. (a) Explain and draw the equivalent section of this composite beam

(2 Marks) (b) Find the position of N.A of the composite section.

(2 Marks) (c) Find the Moment of Inertia and Elastic section modulus of the composite

section. (8 Marks)

(d) Find the maximum stress in steel and concrete if the beam carries a sagging

bending moment of 300KNm. (6 Marks)

(e) Check whether the stress in concrete and steel are within allowable limits.

(2 Marks)

Total 20 marks

DATA

The bending stress in a beam is given by the equation Elastic Critical buckling load, Ncr = π2EI/Lcr2


y y

2500mm

150mm

274.6mm Steel beam 254x254x132 kg/m UC Grade S275 Iyy = 22600cm4 Area = 189cm2 E = 205 kN/mm2

fy = 275 N/mm2

Concrete slab 2500mm x 150mm E = 13.3 kN/mm2 fcd= 16.7N/mm2


Question 4

Figure Q4

Figure Q4 shows a rigid-jointed frame ABCDE pinned to supports at A and E. The plastic moment of resistance of the columns AB and BD is 2Mp each and the plastic moment of resistance of the beam BC is 1Mp. The frame carries a horizontal point load of 40kN at C. (a) Find the values of MP which correspond to the following collapse mechanisms:

i. Plastic hinges at A, B and C. ii. Plastic hinges at A, C,D and E. iii. Plastic hinges at A, B, D and E.

(13 marks) (b) Using suitable supporting calculations, draw the bending moment diagram for

the critical collapse mechanism showing values at A, B, C, D and E (7 marks)

Total 20 marks


40KN

4m

3m

A

C D

E

4m 2MP

MP

2MP

1m

B


Question 5

Figure Q5 Figure Q5 shows a pre-stressed concrete beam. The beam contains eight pre-stressing strands (10mm diameter) at an average height of 100mm from the bottom of the beam.

The beam supports a parking area and so the proportion of the variable load to be considered in the quasi permanent loading condition is 0.6. In service, the beam is simply supported over a span of 12.0m and carries the following loads: Permanent load (including beam self-weight) 9 kN/m

Variable load 25 kN/m

Characteristic breaking load of one strand = 141.30 kN

Initial pre-stress = 70% of UTS

Pre-stress losses = 25% of initial pre-stress Concrete strength at transfer fck = 35 N/mm2

Concrete strength in service fck = 40 N/mm2

For the whole concrete section: Area = 240 x 103 mm2

INA = 17.3 x 109 mm4

Limiting stresses in concrete: 1 N/mm2 in tension

At transfer 0.6 fck in compression;

In service 0.45 fck in compression; 3.8 N/mm2 in tension

Question 5 continued over the page...

●●●●

●●●●

●●●

900

100

200

100

750



(a) Calculate the stresses in the concrete at the top and bottom of the beam:

(i) at transfer; (ii) in service under quasi-permanent loads (13 marks)

(b) Draw the distribution of stress over the height of the beam:

(i) at transfer; (ii) in service under quasi-permanent loads (4 marks)

(c) Compare the calculated values of stress in the concrete with the limiting values

of stress in the concrete: (i) at transfer; (ii) in service under quasi-permanent loads. Comment on the adequacy of the beam

(3 marks)

Total 20 marks

END OF QUESTIONS

Please turn the page for supplementary information


END OF PAPER

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