Adjusting As-Built Surfaces
Updated November 30, 2017
This article applies to:
- RoadEng Civil
As we found at the end of the previous section, survey data (and the resulting surfaces) are not always perfect. It is not the fault of the surveyor if the stripped surface survey extends a few meters beyond the original ground survey; and yet this will produce large fictitious fill volumes. In some cases, it is desirable to create a surface that was not surveyed or to fix obvious glitches in the survey.
Rather than try and modify the surfaces we will first create fixed cross sections from the existing surfaces and then modify the cross sections layers.
Creating fixed cross sections
Start the Location module. File | Open <RoadEngCivil>\As-Built\PartB.dsnx.
This location design is currently displaying four surfaces (extracted from surveyed Terrain files):
|WG.terx||waste surface after the stripping of topsoil|
|UC.terx||under-cut (or sub-cut) surface|
Open the Fixed Section Panel using the button on the windows toolbar, . In the panel click on the Add Section… button to open the dialogue box below.
Figure 1: Add Fixed Cross Section Dialogue
Enable Station Range. Do not enter in a station range at this time.
Uncheck All Point Types. Press theplus button to open the Point Type Selection dialogue box as shown below. Select Auto interval points (20.0m) double click to include. Press OK button.
Figure 2: Selecting Auto Interval Points Set at 20 m
Enter L-Line Station Range from 13740 to 13860. Under New Section Properties turn on Start of Range. Press OK button.
Figure 3: Setting L-Line Station Range
Notice that the Section Editor tree control is now populated with specified sections (start, end, and 20m spacing).
Fixed sections have been created from station 13740 to 13846 (End Station). Because we set the Start of Range property for all sections, no other cross sections are calculated in this 100m range. Although the layer polylines were created from the surfaces (draped) the surfaces are now ignored inside this 100m range. See Fixed Ranges in the Volume Calculations section below for further explanation.
Editing Layer Polylines
We will now edit the as-built surfaces on a cross section to ‘tie them off’ correctly.
Click on the button beside section 13800.0 in the tree to view the section layers. Expand the tree by clicking on the button beside 13800 and further by clicking on the button beside FG. (see Figure 25‑21)
Click on the polyline, 18 points item immediately under FG.
Your screen should appear as shown in the figure below.
Figure 4: FG Polyline Selected for Editing
Note that the FG layer is highlighted magenta and that the points have a small box symbol; this should remind you of a selected feature in the Terrain module.
Right click in the section window and notice that there are four edit modes available (Figure 25‑22 below left). You can also select edit modes in the available Home | Tool Selection button.
Figure 5: Section Edit Modes. The First and Third
apply to Editing Fixed Section Layer Polylines
The Add/Edit Polyline Pt. Tool allows you to edit polyline nodes the same way you edit vertical IPs in the Profile window or feature points in the Terrain module. We will use the Selection Tool for the following steps.
In the Section window scroll and zoom to the upper left corner (figure below).
Figure 6: FG Polyline
Move the selection cursor over the leftmost end point (-14.9 offset) from centerline (last point on the left—see cross position in Figure 25‑23) and left click to select it.
This sets the current point and updates the data at the bottom of the Section Editor Panel. Next, we’ll edit the point to tie the polyline into topo.
Right click and choose menu Add / Edit Polyline Pt. Tool.
Move the cursor over the leftmost point; when it changes to a box , left click to capture the point.
Move the point to connect with topo (note the cursor change as you reach snap range) while retaining the closing slope. Left click again to anchor the point.
The figure below shows the cross section before and after the end point has been tied to topo.
Figure 7: Cross Section 13800, with Intersection Point Edited and Tied to the Topo
You have probably noticed the editing of fixed section is very similar to editing in other parts of RoadEng. The cross-section editor, at the bottom of the Cross Section panel, allows you to do the following:
Add, remove or change a point on any layer or polyline.
Add or remove layers or polylines.
Change the order of the layers (more on this in the Volumes section).
Break or Join polylines.
Add or change point codes.
Enable or disable display and volume calculations for a layer.
Figure 8: Cross Section Editor Controls for Polyline Edit