Capstone Design Topic: Transportation

Date 11/06/2020

DESIGN PROJECT 2

Capstone Design Topic: Transportation

Capstone Design Topic: Transportation Topic 1; After Graduation, you started an

engineering firm, and the first project is to design a two-lane highway in a rural area in

California. The Highway descends a hill, crosses under a bridge, and must shift to a parallel

alignment on level terrain. You will design in the paper the vertical alignment and the horizontal

alignment to meet design standards and minimize earthworks. Diagrams and other specifics are

appended to the next page.

Section to work on:

1. Designed section defined by The natural terrain is flat until station 100 + 00, where a

downhill begins, as shown in the second diagram. Between station 100 + 00 and 120

+ 00, the soil elevation could be approximated by a cosine curve as and x is the

distance (measured horizontally) from station 100 + 00. This leads to an elevation of

7,100 ft before the hill and an elevation of 7,000 ft at station 120 + 00 and onward.

Date Complete by:

2. The design section defined by The highway crosses a bridge at a right angle at station

120 + 00; the bottom of the bridge is 20 ft above the soil.

Date Complete by:

3. Design Section defined by Because of right-of-way reasons, the horizontal alignment

must be straight until station 140 + 00. The transition to the new alignment must be

completed within 3,000 ft, as shown in the plain view.

Some calculations to fulfill this requirement:

DESIGN PROJECT 3

Solution

The Cosine Function is given as:

In this case, it is assumed that the soil cannot be moved within the site. Therefore, the

total cut and fill are computed by taking the integral of the absolute value of the difference

between the natural terrain and the proposed alignment. Therefore, using the parabola for vertical

curves:

y = 7050 + 50cos (?x /2000) ………(i)

120+00

140+00

3,000 ft.

Highway centerline

Bridge

1,000 ft.

Natural terrain

Cross-section of the bridge

DESIGN PROJECT 4

Station = 100 + 00; Elevation = 7,100 ft.

100 + 00

Plan View N

Natural Terrain

Station = 120 + 00; Elevation = 7,000 ft.

Elevation = 7050 + 50cos(?x/2000)

x 20 ft.

A

A’

BB’

C

C’

The cosine function in this case can be formulated in terms of the sine function as either:

y = A sin (Bx) ……………(ii)

y = A cos (Bx)……………. (iii)

Sin ??=! !

??== angle theta

a= length of the opposite side a

h=

DESIGN PROJECT 5

DESIGN PROJECT 6

DESIGN PROJECT 7

References

National Research Council. Transportation Research Board. (, 2003). Transportation

management and public policy of 2003.