Salman bin Abdulaziz University
College of Engineering
Dept. of Civil Engineering
‫جامعة سلمان بن عبدالعزيز‬
‫كلية الهندسة‬
‫قسم الهندسة المدنية‬
Final Exam (Semester I - 2013)
CE 4350 : Highway and Traffic Engineering
Saturday : 23/02/1434 H
Time allowed : (9 h 00 – 12 h 00 : 3 h)
Instructor : Dr. Khaled KHEDER
Student Name
ID
Exercises and Questions
Marks
Exercise n° 1
6
Exercise n° 2
9
Exercise n° 3
7
Exercise n° 4
7
Question n° 1
6
Question n° 2
5
Total
40
1
Exercise n° 1 (6 marks) :
To design a horizontal alignment of a highway. Two straight lines
intersecting at the PI can be connected by an infinite number of circular
curves. Each of these curves may be defined by its radius R or by its
degree of curve D.
Prove your answer about the following :
● The length of tangent : T = R*tan(Δ/2) (1 mark);
● The middle ordinate distance : M = R*(1-cos(Δ/2)) (2 marks);
● The external distance : E = R*(sec(Δ/2) -1) (2 marks);
● The long chord : LC = 2R*sin(Δ/2) (1 mark).
Exercise n° 2 (9 marks) :
A 600 m vertical curve connects a + 4 % grade to a - 2 % grade at station
25 + 60.55 and elevation 648.64.
Give your answer about the following :
● Draw a sketch of this vertical curve (0.5 mark);
● Identify all parameters on this curve (0.5 mark);
● Calculate the location of VPC (1 mark);
● Calculate the elevation of VPC (1 mark);
● Calculate the location of the middle of the curve (1 mark);
● Calculate the elevation of the middle of the curve (1 mark);
● Calculate the location of the VPT (1 mark);
● Calculate the elevation of the VPT (1 mark);
● Calculate the curve elevation at station 24 + 00 (1 mark);
● Calculate the curve elevation at station 27 + 00 (1 mark).
2
Exercise n° 3 (7 marks) :
A 175 acre urban drainage area consists of three different
watershed areas as follows (Table 3 – 1) :
1 – Apartment dwelling areas = 50 %;
2 – Parks = 30%;
3 – Playgrounds = 20 %.
If the time of concentration for the drainage area is 3.0 hours and
assuming that the rainfall intensity curves in figure below (Figure 3 – 1)
are applicable to this drainage area, determine the runoff rate for a storm
of 25 years frequency.
Figure 3 - 1 : Rainfall intensity curves (1 inch = 2.54 cm).
3
Table 3 - 1 : Additional runoff coefficients for urban areas.
Runoff coefficient C1
Type of drainage area
Business :
Downtown areas
0.70 – 0.95
Neighborhood areas
0.50 – 0.70
Residential :
Single-family areas
0.30 – 0.50
Multi-units, detached
0.40 – 0.60
Multi-units, attached
0.60 – 0.75
Suburban
0.25 – 0.40
Apartment dwelling areas
0.50 – 0.70
Industrial :
Light areas
0.50 – 0.80
Heavy areas
0.60 – 0.90
Parks, cemeteries
0.10 – 0.25
Playgrounds
0.20 – 0.40
Railroad yard areas
0.20 – 0.40
Unimproved areas
0.10 – 0.30
Streets :
Asphaltic
0.70 – 0.85
Concrete
0.80 – 0.95
Brick
0.75 – 0.85
Drives and walks
0.75 – 0.85
Roofs
0.75 – 0.95
Exercise n° 4 (7 marks) :
Determine a suitable cross section for a channel to carry an
estimated runoff of 9.6 m3/s if the slope of the channel is 1 percent and
Manning’s roughness coefficient, n, is 0.015.
1
Higher values are usually appropriate for steeply sloped areas and longer return periods because
infiltration and other losses have a proportionally smaller effect on runoff in these cases.
SOURCE : Adapted from Brown et al., Urban drainage design manual, Hydraulic Engineering Circular
N°. 22, 2nd ed., Department of Transportation, Federal Highway Administration Publication N°.
FHWA-NHI-01-021, 2001.
4
Question n° 1 (6 marks) :
Referring to homework n°2 and the textbook Highway and Traffic
Engineering give a summarize (short paragraph) of Highway Surveys and
location. How to apply Remote Sensing and GPS for highway surveying.
Question n° 2 (5 marks) :
Define the following concepts either using full names or using
sketch graphics :
● Normal crown (0.5 mark) :
● Watershed (0.5 mark) :
● Runoff (0.5 mark) :
● Downstream (0.5 mark) :
● Rainfall (0.5 mark) :
● Give the main steps of the design procedure for subsurface drainage :
1 - (0.5 mark) :
2 - (0.5 mark) :
3 - (0.5 mark) :
4 - (0.5 mark) :
5 - (0.5 mark) :
.‫باهلل‬
5
‫إستعن‬