TW53
UNIVERSITY OF BOLTON
ENGINEERING, SPORTS & SCIENCES
BEng (Hons) CIVIL ENGINEERING
SEMESTER 2 EXAMINATION 2014/2015
ADVANCED STRUCTURAL ANALYSIS & DESIGN
MODULE NO. CIE6001
Date: Friday 29 May 2015
INSTRUCTIONS TO CANDIDATES:
Time:
10.00 – 1.00
There are FOUR questions
Answer ALL questions
All questions carry equal marks
Total 100 marks for the paper.
Extracts from EC3 to be used with
Question 2 are included with this
paper.
Page 2 of 12
Engineering Sports Sciences
BEng (Hons) Degree in Civil Engineering
Semester 2 Examination 2014/2015
Advanced Structural Analysis & Design
Module CIE6001
Question 1.
80 kN
B
3m
2Mp
C
D
60 kN
Mp
2m
E
A
Mp
3m
F
4m
2m
6m
Figure Q1
Figure Q1 shows a rigid-jointed frame ABCDEF pinned to a support at A and fixed to
a support at F. The plastic moment of members AB and DEF is Mp, and member
BCD is 2Mp.
There is a vertical point load of 80 kN at C and a horizontal point load of 60 kN at E.
a. Find the values of MP which correspond to the following collapse
mechanisms:
i) Plastic hinges at B, C and D.
ii) Plastic hinges at D, E and F.
iii) Plastic hinges at B, D and F.
iv) Plastic hinges at B, E and F.
(3 marks)
(3 marks)
(4 marks)
(5 marks)
b. Draw the bending moment diagram for the critical collapse mechanism
showing values at the joints and the point load positions.
(7 marks)
c. Sketch an extra possible mechanism and explain how you know that it is not
the critical mechanism.
(3 marks)
(Total 25 marks)
Please turn the page
Page 3 of 12
Engineering Sports Sciences
BEng (Hons) Degree in Civil Engineering
Semester 2 Examination 2014/2015
Advanced Structural Analysis & Design
Module CIE6001
Question 2
a) List four examples of imperfections that affect the buckling behaviour of real
slender columns.
(5 marks)
b) A 6 m long UKC 203x203x60 is completely fixed at one end, while its other
end is simply supported about it minor axis (lcr = 0.7L) and free to deflect to its
major axis (lcr = 2L). The column section is shown in Figure Q2.
i)
Determine the buckling resistance of the column about both axes using
EC3 method. Comment on the results.
EC3 buckling formulae sheet is attached at the end of this paper.
(12 Marks)
ii) Calculate the axial load capacity about the critical axis using the PerryRobertson formula.
c 
1
 y  1  0.003  cr   1  y  1  0.003  cr 2   y cr
2
4
Where
 y  235N / mm
2
 2E
 cr  2


(5 Marks)
Lcr
r
iii) Comment on the results from Parts (i) and (ii).
(3 Marks)
Total 25 Marks
UKC 203x203x60:
Height of the column: L= 6m
A= 76.4 cm2
Iy = 6120×104 mm4
Iz = 2060×104 mm4
h = 209.6 mm
b = 205.8 mm
tw = 9.4 mm
tf = 14.2 mm
ry = 89.6 mm
rz = 52 mm
E = 210 kN/mm2
fy = 235 N/mm2
Partial safety factor 𝛾𝑀1 = 1
Cross-section is Class 1
 2 EI
N cr 
2
 cr
205.8 mm
14.2 mm
z
9.4 mm
y
y
209.6 mm
z
Figure Q2
Extracts from EC3 to be used with Question 2 are included in Appendix A.
Please turn the page
Page 4 of 12
Engineering Sports Sciences
BEng (Hons) Degree in Civil Engineering
Semester 2 Examination 2014/2015
Advanced Structural Analysis & Design
Module CIE6001
Question 3
Part A – BEAM DESIGN
1350mm
175mm
N
A
750mm
457mm
140mm
500mm
Figure Q3
Figure Q3 shows a pre-stressed concrete beam. The beam contains seven prestressing strands (12.9mm diameter, 7 wire super strand) at a height of 140mm from
the bottom of the beam.
The beam supports dwellings and so the proportion of the variable load to be
considered in the quasi permanent loading condition is 0.3. In service, the beam is
simply supported over a span of 7.5m and carries the following loads:
Permanent load (including beam self-weight)
55 kN/m
Variable load
45 kN/m
Characteristic breaking load of one strand
Initial pre-stress
Pre-stress losses
Concrete strength at transfer
Concrete strength in service
For the whole concrete section:
Second moment of area of concrete section
fck
fck
Area
INA
= 186 kN
= 70% of UTS
= 25% of initial pre-stress
= 35 N/mm2
= 45 N/mm2
= 523.7 x 103 mm2
= 26.8 x 109 mm4
(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
(12 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) Suggest two ways to improve the capacity of the beam
(2 marks)
Question 3 is continued
Please turn the page
Question 3 (continued)
Page 5 of 12
Engineering Sports Sciences
BEng (Hons) Degree in Civil Engineering
Semester 2 Examination 2014/2015
Advanced Structural Analysis & Design
Module CIE6001
Part B - SLAB DESIGN
For a post stressed 285mm deep reinforced concrete flat slab, supported by columns
on a square grid of 10m centres, use the load balancing method to choose the
profile, number and size of tendons within the slab.
Calculate the balanced moment at SLS using an imposed load of 5 kN/m2 and a
superimposed dead load of 1.25 kN/m2 applied to the slab.
Use the values in the table below for commonly used strand in the UK and assume
that the minimum distance from face of concrete to centre line of pre-stressing strand
is 65mm. Further assume an initial pre-stress loss of 20% of the characteristic force,
10% loss at transfer and 20% loss at service. Do not calculate the stresses within the
slab.
Strand type
12.9 ‘Super’
15.7 ‘Super’
15.7 ‘Euro’
15.2 ‘Drawn’
Nominal
tensile
strength
(MPa)
1860
1770
1860
1820
Nominal
diameter
(mm)
Cross –
sectional
area (mm2)
12.9
15.7
15.7
15.2
100
150
150
165
Characteristic
value of
maximum
force (kN)
186
265
279
300
Maximum
value of
maximum
force (kN)
213
302
319
342
Draw an indicative sketch section of the slab, showing the output of your calculations.
This does not need to be to scale.
(7 marks)
(Total 25 marks)
Please turn the page
Page 6 of 12
Engineering Sports Sciences
BEng (Hons) Degree in Civil Engineering
Semester 2 Examination 2014/2015
Advanced Structural Analysis & Design
Module CIE6001
Question 4
PART A - ECCENTRIC BOLTED CONNECTION
The L shaped bracket shown in the figures is connected to a steel column 206mm
deep with 6 NoM20 (8.8) bolts. The bracket is formed from a UB 305x127x48kg/m
steel section with the following properties:
Web thickness
Flange thickness
Depth of section
Width of section
8.9mm
14mm
310mm
125mm
A factored vertical force of 40kN is applied at the location shown in the plan view of
the bracket.
(i) What are the in and out of plane moments in the bolt group?
(4 marks)
(ii) What are the maximum tension and shear forces in the bolts carrying the greatest
tensile force? What is the compression force at the base of the UB305 bracket?
(8 marks)
centre line of column
206mm
A
A
Vertical load applied to L
shaped bracket at
location shown
700mm
90mm
Figure 1
PLAN VIEW ON BRACKET
400mm
Question 4 continued on next page…..
Please turn the page
Page 7 of 12
Engineering Sports Sciences
BEng (Hons) Degree in Civil Engineering
Semester 2 Examination 2014/2015
Advanced Structural Analysis & Design
Module CIE6001
Question 4 (PART A continued)
85mm
b1
70mm
b2
70mm
b3
85mm
90mm
Figure 2
SECTIONAL ELEVATION A-A ON BOLTED ENDPLATE
SHOWING SETTING OUT OF BOLTS
Question 4 PART B
In answering Question 4 PART B please tear out and use the multiple choice
marking sheet in Appendix B
Q4B - 1
Choose the bending moment diagram (BMD) that matches the structure
shown
(2 marks)
A
B
C
D
Question 4 continued on next page…..
Please turn the page
Page 8 of 12
Engineering Sports Sciences
BEng (Hons) Degree in Civil Engineering
Semester 2 Examination 2014/2015
Advanced Structural Analysis & Design
Module CIE6001
Q4B - 2
Choose the summary diagram showing the nature of the member forces
that matches the structure shown [C is compression, T is tension and 0 is
zero force]. All horizontal and vertical members in the structure are of
equal length
(2 marks)
A
B
C
D
Q4B - 3
Choose the answer in the table that matches the structure shown.
Consider both the value and the nature of the forces in Members 1 and 2
.
(4 marks)
Member 1
Member 2
A
Zero force
50 kN compression
B
30 kN compression
50 kN tension
C
Zero force
50 kN tension
D
30 kN tension
50 kN compression
Question 4 continued on next page…..
Please turn the page
Page 9 of 12
Engineering Sports Sciences
BEng (Hons) Degree in Civil Engineering
Semester 2 Examination 2014/2015
Advanced Structural Analysis & Design
Module CIE6001
Q4B - 4
Choose the bending moment diagram (BMD) that matches the structure
shown
(2 marks)
A
B
C
D
Q4B - 5
Choose the bending moment diagram (BMD) that matches the structure
shown. Consider the values of the bending moments given in the answer
choices
(3 marks)
A
B
C
D
(Total 25 marks)
End of Questions
Please turn the page
Page 10 of 12
Engineering Sports Sciences
BEng (Hons) Degree in Civil Engineering
Semester 2 Examination 2014/2015
Advanced Structural Analysis & Design
Module CIE6001
APPENDIX A – Extract from EC3 to be used with Question 2
Please turn the page
Page 11 of 12
Engineering Sports Sciences
BEng (Hons) Degree in Civil Engineering
Semester 2 Examination 2014/2015
Advanced Structural Analysis & Design
Module CIE6001
APPENDIX A – Extract from EC3 to be used with Question 2
Please turn the page
Page 12 of 12
Engineering Sports Sciences
BEng (Hons) Degree in Civil Engineering
Semester 2 Examination 2014/2015
Advanced Structural Analysis & Design
Module CIE6001
APPENDIX B
Multiple choice answer sheet to be used with Question 4 PART B
Please tear out of the exam paper and enclose with your exam script
Student number:
Questions
Marks
(please
leave this
column
blank)
Circle the correct answers
Q4B - 1
A
B
C
D
Q4B - 2
A
B
C
D
Q4B - 3
A
B
C
D
Q4B - 4
A
B
C
D
Q4B - 5
A
B
C
D
TOTAL
It is essential that your answers are clear, as ambiguous answers and
crossing out may make it impossible to award marks for parts of this question.
END OF PAPER