Most cross sections in an alignment are generated dynamically by the applied template. Templates can be very flexible and "smart" so that they produce the desired cross section for many ground and alignment configurations. However, if a template can't be made to fit a certain situation or if it isn't worth the trouble to make a new template for a rare situation it is possible to create a Fixed Cross Section which can then be edited with the mouse (and other tools).
Fixed cross section defining points:
A Fixed Cross Section is does not change it's shape when the alignment changes. The position of the surfaces may change when the alignment changes. See Alignment Changes below.
You can create a Fixed Cross Section from an existing template cross section.
You can modify, add or remove any part of a fixed cross section (points, poly-lines, layers, etc.)
You can exclude template generated cross sections between fixed cross sections if desired.
Creating and Editing
The Section Editor Panel allows creation, viewing and modification of Fixed Cross Sections . When a fixed section is current, the Section Window allows you to edit it graphically.
Alignment Changes
If either the horizontal or vertical alignment changes after a fixed section has been created, RoadEng will adjust the Fixed Section surfaces as follows.
a) Topo, Sub-horizons (1,2 and 3) and Stripping will remain unchanged.
b) Template surfaces will maintain their shape but will move horizontally or vertically with the alignment.
NOTE: If the alignment changes significantly after the Fixed Cross sections have been created they may become inaccurate (due to station and orientation changes). To fix this it may be nessecary to Reload some of the surfaces. This can be done with the Layer Operations dialog in the Fixed Section Editor.
Issues Converting from Templates to Fixed Sections
In some circumstances, a Template Cross Section will not convert directly to a Fixed Cross Section. This is because Fixed Cross Sections are based on a series of layers representing the construction sequence (see Merged Surface). Whereas, Templates are more flexible and can model geometry based a series of Fragments.
If you get a warning when converting from Templates to Fixed Cross Sections the following steps are recommended:
Check the order of each layer in the Fixed Cross Sections. Remember, that processing of cross sections is construction sequence.
Check that the Volumes attribute is turned where appropriate in each Fixed Cross Section.
Use the hatch tool to make sure cut/fill areas are being calculated properly.
