Agriculture Reference
In-Depth Information
with other elements as the proposed shape of the land or series of paved
surfaces between buildings. Sections are useful when structures are
involved, to allow the designer to better see how the structure meets the
ground and then transitions to the adjacent landscape. Section drawings
are usually included in a construction drawing package. Sections are
drawn to provide greater detail not easily accomplished in the plan view
of a grading drawing and to guide the contractor. Sections can often
explain the designer's grading intent to a contractor and others more
clearly than the grading plan view alone. Although both the plan and
section are two-dimensional drawings, the section helps to better visu-
alize the three-dimensional aspects of the grading plan.
Construction of a section drawing is a multi-stepped process. Refer
to Figures 7.19-A-7.19E to follow the process.
step a requires two aCtions
First, draw a section line (sometimes referred to as a section cut line) over
the topographic or grading plan and label it
Section AA
. The plan should be
at the same scale the designer is using to develop the grading plan.
Next, draw a series of contour lines that will have the same horizontal
scale as the topographic plan; however, the vertical scale is usually exag-
gerated by three times the horizontal scale. So if the plan were drawn at 20
scale, the vertical scale would separate each contour line by the equivalent
of three feet shown on the 20 scale. The contour lines shown below the
topographic plan are drawn so that each contour is separated by three-foot
intervals on a 20 scale with each contour labelled.
step B
Go to Section AA on the topographic map, and at each point where the
Section AA line intersects a contour on the plan, draw a perpendicular line
down to the equivalent contour line stacked below the plan. In this case we
have started in the middle of the topographic plan at the 350-contour line
and dropped two perpendicular lines to the 350-contour line below. Nor-
mally, the designer would start the process going from left to right rather
than starting in the middle.
