Spectra Precision Survey Pro v3.80 Recon iPAQ User Manual - Manual (Page 151)

Screen Examples
143
Slope Staking
The ultimate purpose of the slope staking routine is to locate where
the design slopes that extend from the ends of a roadway intersect
with the actual terrain at various stations. This intersecting point is
called the catch point.
Before a road can be slope staked, it must first be designed. The first
step to designing a road is to define the path of the road’s centerline.
This line can be in the form of a polyline or an alignment. Creating
this line is explained in detail starting on Page 54.
Once the centerline is defined, the cross-sectional profile of the road
must be defined. This profile is then superimposed onto the
centerline at a specified station interval. The final step is to go out in
the field and stake the catch points at each of these
stations.
A road’s cross sectional profile always consists of left and
right road surfaces, which are tangent at the centerline.
An optional curb or ditch can also be included in the road
profile. The final segment of a road’s profile has either a
specified positive slope or a specified negative slope,
which ends at the catch point. This final segment
attaches to the edge of the road at what is called the
hinge point since this segment can hinge between a
positive and negative slope around this point.
The Slope Stake routine can automatically determine if
the outer slope of the road profile should have a positive
or a negative slope based on the location of the hinge
point. If the hinge point is located below the surface of
the terrain, a positive slope is selected and a cut will be
required, starting at the catch point. If the hinge point is
located above the surface of the terrain, a negative slope
is selected where a fill will be required, starting at the
catch point.
The illustrations here show examples of a road that
requires a fill on both sides; a road that requires a cut on
both sides; and a road that requires a fill on one side and
CL
Fill Area
Hinge Points
Catch Points
Terrain
A road requiring a fill on
both sides.
CL
Cut Area
Hinge Points
Catch Points
Terrain
A road requiring a cut on
both sides.
CL
Cut Area
Hinge Points
Catch Points
Terrain
Fill Area
A road requiring a fill on one
side and a cut on the other side.