1) The document contains instructions for an exam on the design of bridges. It includes 6 multiple choice questions worth 1 mark each, asking about Courbon's theory, T-beam bridges, Pigeaud's method, and ratios for bridge deck design. 2) Question 2 worth 14 marks asks students to design the longitudinal girder of a T-beam bridge given specifications such as span, carriageway width, girder spacing and thickness, slab thickness, loading, and materials. 3) Question 3 worth 10 marks asks students to find the design bending moment for the longitudinal girder from question 2, if the live load is changed to IRC Class A wheeled (two lane) loading.

1. 1
WALCHAND INSTITUTE OF TECHNOLOGY, SOLAPUR
B.E. Part-II, 2018-19
In-Sem. Examination - III
Sub: - Elective- II- Design of Bridges Max. Marks: 30
Day and Date: - Wednesday 7/ 03 /2019
Time: - 4.10 pm to 5.10 pm
Instructions: i) All questions are compulsory.
ii) Write answer of the MCQ/ objective type question only on first page of answer book.
iii) Draw neat labeled diagrams whenever necessary.
iv) Assume suitable data wherever necessary.
Q.
No
.
Su
b
Q.
No.
CO No. Contents Ma
rks
Total
Marks
1
1
2
3
4
5
6
C423.C2
C423.C2
C423.C2
C423.C2
C423.C2
C423.C2
Multiple choice questions
Courbon’s theory is applicable only when the ratio of span to width
is
a) Greater than 2 but less than 4
b) Greater than 4
c) Greater than 4 but less than 6
d) None of these
T- Beam bridges are most commonly adopted in the span of
a) 5-8m b) 10-25m
c) 30-50m d) None of these
Pigeaud’s method is most useful when K is more than
a) 0.44 b) 0.50
c) 0.55 d) 0.60
Pigeaud’s theory is used to calculate
a) Bending moment b) Load factor
c) Effective span d) Impact factor
Load factor ‘K’by Courbon’s theory for uniform MI is given by,
a)
∑ 𝑊
𝑛
[1 +
𝑛 𝑒 𝐼1 𝑋1
∑ 𝐼𝑖 𝑋𝑖
2] b)
∑ 𝑊
𝑛
[𝑛 +
𝑒 𝑋1
∑ 𝑋2
]
c)
∑ 𝑊
𝑛
[1 +
𝑛 𝑒 𝑋1
∑ 𝑋2
] d)
∑ 𝑊
𝑛
[𝑛 +
𝑒 𝐼1 𝑋1
∑ 𝐼𝑖 𝑋𝑖
2]
According to Courbon’s method of analysis, the ratio of the depth of
cross to main girders in a T beam slab bridge deck should be at least
a) 0.5 b) 0.75 c) 1 d) 1.5
1
1
1
1
1
1
6

2. 2
2 C423.C2
Design the longitudinal girder of T beam bridge
Consider following data:
 Effective span – 18 m
 Carriage way width- 7.5m, curb- 600 mm wide and 250 mm
depth
 Spacing of longitudinal girders and cross girders- 3 m c/c
 Thickness of longitudinal girder and cross girder - 300 m
 Slab thickness- 250 mm, wearing coat- 100 mm thick
 Live load- IRC class AA tracked
 Use M- 25 concrete and Fe 415 steel
( Assume necessary additional data if required)
14
3. C423.C2
Find the Design bending moment for longitudinal girder of the Q
No. 2, if the live load is replaced by IRC Class A wheeled (two
lane)
10