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Horizontal Alignment
Use the Geometry › Point-Point Line function in
CAD mode to draw geometry lines on the straight
portions of the road centerline. Use the DTM jump
“Shift d” key, or the Grab-All snap mode to jump to
centerline points.
Select Alignment › Horizontal › Graphical Insert from
the ROADS mode. Insert a start PI on the first
centerline point using the “Shift d” key. All the PI
points will be located at the geometry intersection
points, therefore use the “I” key to jump on these
geometry intersections. Enter the last PI point the
way you entered the start PI.
To calculate the curve radii, use the Alignment › Horizontal
› Fit Curve function. Before you use this
function, you need to rename one point near the center
of each curve with unique names, e.g. “CNTR1”.
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Now select Alignment › Horizontal › Fit Curve.
Indicate the curve number and the name of a point on the curve. Press
OK.
The curve radius for curve 1 can now be entered into the Horizontal
Alignment spreadsheet. Repeat this procedure for all
the remaining PI's.
Save the Horizontal data and coordinate the alignment
at the desired intervals. Extract cross sections from
the ground surface at these intervals.
Vertical Alignment
The vertical alignment needs to be extracted from the
ground model, at the centerline of the road. To do
this, you need to transfer a point at offset 0 from
the ground gross section layer to the Layer 128.
Civil Designer uses Layer 128 as a “Scratch pad” layer
for various calculations. It will expect the vertical
alignment levels in Layer 128 when generating edge
levels.
Select Section › Interpolate from the ROADS
menu.
Press OK
 Enter
the Offset from centerline to interpolate as 0.000 and
press ADD. Press OK to continue.
A point on the centerline of the road, at the ground
level will be transferred to Layer 128. This level can
now be raised or lowered, as needed using the
Section › Absolute Change function.
Edge Levels
You can generate edge levels using one of two possible
methods.
Method 1
Use this method if you want to re-design the existing
super elevation of the road.
Use the Alignment › Edge Levels › Edit Super /
Slave Super function to specify the edge levels.
Run Alignment › Edge Levels › Generate Levels
to calculate the edge levels using the vertical
alignment points stored in Layer 128.
Remember to change the Layer for edge levels option to
your Design Surface and not Layer 128.
Method 2
Use this method if you would like to work with the
existing super elevation of the road. The basic idea
here is to generate edge levels manually by picking
them up from the original ground cross-sections.
Select Section › Interpolate from the ROADS
menu.
Press OK and add the following offsets to the list:
The reason why we use offsets of 0.5 and –0.5 instead of 0.0 is because
the surveyed centerline may not exactly follow the
specified horizontal alignment. The actual centerline
may therefore be a little to the left, or a little to
the right of the surveyed centerline.
The offsets 3.1 and –3.1 represent a point on the
existing carriageway, close to the road edges.
Extending a line from offset 0.5 to offset 3.1 should
result in an accurate crossfall for each cross
section. Press OK.
The cross section points on your design layer
currently at offset 3.1 and –3.1 can now be extended
at the current crossfall to the desired road widths.
Use the Section › Expand Shrink function to do
this.
Press OK
Press OK to move the point currently at offset –3.1, 5.5 meter to the
left at the current crossfall. The point will then be
at offset -8.6. Do the same for the right hand side.
Apply Template
If you used Method 1 to generate edge levels, or your
design layer has only 3 points per cross section, you
can use the Apply Template function.
If you used Method 2 to generate edge levels and you
have more than 3 points per cross section on your
design layer you must use the Add Template function
instead of Apply Template. Add template simply adds
compulsory and Cut/Fill details, as specified in the
template, to the edges of the specified layer.
Select the Tools › Template Paths option and specify
and number the templates to be used in the design.
Select the Area/Volume › Add Template option.
Specify the template number to be used. Press OK
Define the Start chainage and Stop chainage
as well as the Base layer and
Batter layer as shown. Press OK to add the
template.
If you used Add Template and you need to re-apply the
template. You cannot simply run Add template again,
because the cut and fill details will be added to the
edges of whatever is currently in your design layer.
You therefore need to remove the batter points before
adding the template again.
To do this, select Section › Remove Points.
Press OK
Press OK to remove the left hand side cross section points from PLC –3
to –99. Similarly you can remove the right hand side
points by specifying:
Now you can re-add the template. |
