Spectra Precision Survey Pro v4.5 Ranger User Manual - Manual (Page 148)

User’s Manual – Conventional Mode
138
Slope Staking
The ultimate purpose of the slope staking routine is to locate where
the outer slopes of a predefined roadway intersects with the surface of
the terrain at various stations so the point where a cut or a fill begins
can be determined. 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
these lines is explained in detail, starting on Page 44.
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 cut on the
other side.
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.