drawing. Refer to the example in figure 3-5, and read
the following explanation:
1. STATION NUMBERS. The station numbers
are lettered horizontally below the profile and grade line
and are centered on the appropriate vertical grid line.
2. ELEVATIONS. At the bottom of the sheet, the
profile and grade-line elevations for each station are
lettered vertically. The grade-line elevations are lettered
just above the profile elevations. Any station numbers
other than full stations are noted as plus stations,
vertically, just outside the bottom border.
3. CUTS AND FILLS. Above the profile and
grade-line elevations are lettered the cuts and fills. They
are also in a vertical position. The grade points, or
points where the profile crosses the grade line, are also
noted in this row. They are designated by the word
GRADE lettered vertically above the grade-point
4. DITCHES. The procedure for dimensioning
ditches has two steps as follows:
a. First, draw extension lines from the ends of
a ditch or any point in the ditch where the ditch grade
changes. These lines should be extended downward, and
dimension lines (with heavy arrowheads) should be
drawn between them. These extension and dimension
lines should be drawn heavier than normal so they may
be distinguished from grid lines.
b. Next, above the dimension line, letter the
information necessary to describe the ditch. If the
lettering is crowded, you may also use the space below
the line. You should furnish the following information:
percent of grade of the ditch, depth relative to center
line, type of ditch, and width of ditch. Give the elevation
and station at the ends of the ditches and at changes of
5. VERTICAL CURVES. Each vertical curve on
the grade line is also dimensioned. Draw extension lines
upward from the PVC and PVT. Then draw a dimension
line between the extension lines and letter the length of
the curve above. Letter the station and elevation of the
PVC, PVI, and PVT vertically over these points and
above the dimension line.
6. CORRELATION WITH PLAN. All points on
the profile and grade line coincide with center-line
points on the plan. For example, you should show the
beginning and ending of construction on the plan view
and also on the profile and grade line. Also, note the
elevations at these points.
7. DRAINAGE STRUCTURES. Dimension all
drainage structures, such as pipes and culverts, by notes.
Note the station number, size of opening, length of pipe,
and flow-line elevation.
8. TITLE. In this example, the title, PROFILE
AND GRADE LINE is lettered below the ditch
dimensions. Below this are noted the horizontal and
SEQUENCE OF CONSTRUCTION
In constructing a road, the construction crews
should follow a specific sequence. First, they clear the
area through which the road must pass of trees, stumps,
brush, boulders, and other debris. The width of the
clearing varies greatly but is always at least 12 feet
greater than the roadway width; that is, the crew should
clear at least 6 feet behind the construction limit on both
sides of the road.
The next step is the grading operations and the
laying of cross-drain pipes, or culverts. The grading
operations are carried on by the Equipment Operators
until the subgrade is completed. In fill areas, the grading
is brought up in layers and compacted. In cuts, the
excavation is carried on until the subgrade elevation is
reached, and then the earth is compacted. Throughout
this step of the road construction, workers place the
culverts when and where required. These culverts are
placed in their appropriate positions and at the required
slopes according to the roadway plans.
After the subgrade is completed, Equipment
Operators place abase course on the subgrade. The base
course material can be gravel, sand, crushed stone, or
more expensive and permanent materials. Finally, the
Equipment Operators place a surface course over the
base. This material can be sand, asphalt, blacktop,
concrete, or similar materials.
In some cases, traffic may be allowed to travel over
the subgrade itself. In others, traffic may require only a
gravel or stone surface. A high-speed road, however,
requires abase and a hard, durable surface.
As you should recall from your study of the EA3
TRAMAN, a section is a view of an object that has been
cut by a plane that is perpendicular to the line of sight.
For road sections, the line of sight is perpendicular to
the roadway center line.
Sections are used for a variety of purposes during
the various phases of road design and construction. One
purpose is to define what the materials and design