What follows is a general discussion on ways to apply the Road functions. It is not necessarily a step-by-step procedure. It also does not attempt to cover the many possible circumstances that can be encountered when dealing with cross-sections.
First, you might establish a road design template. See the section on Road Templates for details on the creation of templates. This is only used much later when you come to expand the basic road profile while calculating areas. However, because a road template is a shared resource that you will probably use and re-use for many future jobs, it does no harm to start a library of templates straight away.
In addition, because defining a template involves a rigorous step-by-step approach, and because a designed template can be tested in any condition straight away, it often exposes logical problems at this preliminary design stage that could prove very awkward if caught later on.
Road templates can define single or dual carriageways. The program works on one template per job system. This means that in any one template you are able to describe all the circumstances under which the road profile is altered in response to any particular cut or fill condition. This is great in theory, but rarely achievable in reality as one usually ends up with two or three templates on any road more than a few kilometres long. The main reason for this tends to be the different materials through which a road passes.
When you store a template, the template file itself is written to your chosen resource directory. You also have the option of adding that template to a design file list. Each road design file has a list of templates that can be accessed by that road. When you later specify that you want to apply template number 5 for example, the fifth template from the list in that road design file is applied.
[TemplateIndex]
1,c:\civdes6\resources\dual_ntc.tem
2,c:\civdes6\resources\rural_a.tem
3,c:\civdes6\resources\rural_b.tem
4,d:\geluk\normal.tem
5,d:\geluk\special.tem
6,d:\geluk\passing.tem
7,e:\testing.tem
The next logical operation is to gather your basic ground cross-section data. There are two possible sources for this data:
Imported from external sources.
Extracted from a digital terrain model under the Terrain main menu.
Assume for the moment that it is the former. You need an ASCII file of the sections that is in a form readable by Civil Designer. This file might have been obtained from an aerial survey company, or typed in with a word processor/spreadsheets program, or exported from some other software. The order of the sections, and the number of them, are immaterial. All you have to do is Import them.
The alternative method involves coordinating the horizontal alignment under the Horizontal Alignment in the Road menu. When this has been defined, you can extract sections using Cross Section Extract.
Once read in, the first thing you do is to check your data or at least a representative sample of sections. You can do this using the cross-section editing functions under Section in the Road menu. Either do a graphical edit and repeatedly use the PGDN key to bring up the next section, or list them. If you are uncertain, do both. Check that the chainages you expect are there and that the data conforms to sensible limits. The chainage values are displayed in the bottom left hand corner of the screen. It is easy to miss a single column position when specifying the import details, and end up with elevations 100 or 1000 metres out.
Now a geometric alignment is required. The horizontal alignment is done using the Horizontal Alignment function in the Road menu. It is not essential to have either of them, but obviously certain facilities later on will be dependent upon this information being present. There are times though, rehabilitation work for example, when the entire road design is dictated by in-situ conditions and the whole quantification operation is carried out without an alignment.
A horizontal alignment calculates the coordinates of every chainage point. These are stored with the section data, and be added to the terrain file as well. The latter is not normally necessary, unless the chainage points are needed for certain survey calculations. Both the section extraction function and plan plotting function (Plot) access the road file directly.
The vertical alignment can be typed in, or generated on the screen graphically using the mouse. Once established, the elevations of each chainage point are calculated and stored in a reserved layer - Number 128. There is one point in the case of a single carriageway, two for a dual carriageways. This layer can be listed and edited just like any other. So, if you have a localized anomaly, just overwrite the theoretical values manually. In the case of rehabilitation work, this might be the whole job.
Most of the data from the geometric alignment, and other road functions, is stored in the Road Design file. For road 12, this file has a name like MIDMAR.12.DES. It is a comma delimited ASCII file that can be inspected at will. Scanning this file is a quick way of catching up on the state of data generation if you have been absent from the job for an extended period.
After a geometric alignment, you need to specify the carriageway behaviour, such as the stretches that have a crossfall, the stretches in superelevation, how much the road widens, what sort of slopes are applied, which template to apply and so on. You can use the Edge Levels function. The details you specify can be linked to the horizontal alignment (usually rural roads) or independent of it (normally township roads).
Once control information is available, the carriageway edges are calculated. This creates a basic three-point cross-section on single carriageways, and four points plus the median details on dual carriageways.
At this stage, you have a ground layer and a designed road layer that needs to be connected to it. Use the functions under Area/Volume to do this.
The first time you run the Area/Volume functions on any piece of road, you normally use either Set Batters or Apply Template. The former simply connects the extremity points of your design layer to the ground with whatever batter conditions you specify at that time. The latter adds the template shoulder conditions to your section extremities, and then connects to the ground with whatever batter conditions you specified in that template.
It is sometimes desirable not to calculate, or otherwise handle, certain chainages. Using the Index you can 'switch off' selected chainages for a certain task, and later switch them on again.
After applying the Area/Volume functions, it is a good idea to visually check a representative sample of the processed sections to make sure that they meet your expectations. It is sometimes also beneficial to review the layer data in Index under Tools, to make sure that reasonable end areas were calculated and stored.
With your end areas in the bag, the volume and mass haul is the last of the primary calculations. The volume functions under Area/Volume provide this service. The options are such that different material conditions are catered for, and all the required figures for cut, fill, topsoil, bank areas and so forth are provided. The Masshaul volumes can be dumped as an ASCII file for subsequent plotting.
Unfortunately, roads are rarely consistent along their entire length and site considerations often dictate a design procedure that is far from conventional in approach.
To overcome special design requirements, use your imagination and the freedom that the software provides. Remember that you do not have to have a terrain file or survey data, you do not have to have a horizontal or vertical alignment, and there is no set procedure that has to be followed through the programs.
The key to dealing with most localized non-standard situations is the combined use of the special editing facilities under Section, and the control over areas and volumes that can be exercised with the Index functions.
The Section Editing functions, as well as offering powerful graphical control over individual sections, also provide a number of helpful functions for dealing with changes over a sequence of sections. Items can be progressively stretched and shrunk and/or raised and lowered. Chunks of data can be extracted and moved from one layer to another, and features that do not conform to the road alignment - such as a straight retaining wall - can be introduced.