Building Road Body Layers¶
With the Gemini surface generator, we can build Gemini theoretical layers.
The surface generator uses tables under road parameters (manual method) and tunnel. The tables are obtained by importing other road model formats (VIPS), from predefined templates, or by manual entry.
Road parameters are described with the following tables, among others:
- Surface descriptions
- Side area
- Substructure
- Superstructure
- Tunnel
Note
Currently, we only partially support the construction of railway-VIPS.
Every time we make a change in road or tunnel parameters, we must rebuild the layer(s).
The Build surfaces... function can be found by right-clicking in the cross-section editing window.
Physical Layers in the Profile¶
Based on the physical layers in the cross-section, we create several temporary "phantom layers" before building theoretical layers in the cross-section.
- 80: TOP SOIL
- 81: TOP ROCK
- 82: TOP REPLACEMENT MATERIALS
- 83: TOP TOPSOIL
- 84: TOP VEGETATION
- 96: TOP REPLACEMENT MATERIALS AND LOWER
- 97: TOP SOIL AND LOWER
- 98: TOP THEORETICAL LAYER
- 99: TOP PHYSICAL LAYER
A "phantom layer" is a combination of other layers. The combined layer is the highest of the layers included.
For example, 81: is a combination of layers 6-10.
Layers 6, 7 and 8 are rock layers. Layer 81 is top rock.
We use the "phantom layers" during construction. We can especially mention that TOP REPLACEMENT MATERIALS AND LOWER is used during construction when removal of topsoil/vegetation is defined. Similarly, TOP SOIL OR LOWER is used when mass replacement is defined.
Surface Descriptions¶
We describe the road surface with surfaces (in the same way as in VIPS). The surfaces are divided into eight main groups. Within each group, there can be several sub-surfaces, from 01-99. The surface number therefore consists of one number that refers to a main group and another number, separated by a period, that indicates the sub-surface, for example 1.01.
| Main group no. | Main group name |
|---|---|
| 0 | Median |
| 1 | Driving lane |
| 2 | Shoulder |
| 3 | Additional surfaces |
| 4 | Ditch |
| 5 | Rock cut |
| 6 | Soil cut |
| 7 | Fill |
| 8 | Leveling |
| 9 | Other surfaces |
Surfaces on the left side of the centerline are given with a negative sign. The surfaces are assembled in ascending surface number order. This applies to both the main groups and the sub-surfaces within each group.
Surface group 5 can be defined to stop against rock layers, while surface group 6 can be defined to stop against soil layers. Similarly, we can stop fill against a physical layer.
Example of road in soil and rock profile
Additional surfaces can be used to describe elements alongside the road that are closely related to it, for example noise barriers, sidewalks, ramps, and pedestrian and bicycle paths.
Example of road with pedestrian and bicycle path
We refer to the dialog help for more detailed description.
Side Area¶
We define the side area with the tables Rock shelf, Minimum ditch depth, and Ground leveling.
With the rock shelf table, we can define how far in from the top of the rock cut we should go before continuing with soil cut.
We use ground leveling to define fill surfaces that should be placed on top of the ordinary road surface or cut surfaces to indicate that some of the side terrain should be leveled. Examples of use can be construction of noise barriers and leveling of side terrain.
A* = Ground leveling, B* = Distance
We refer to the dialog help for more detailed description.
Substructure¶
We define the substructure with the tables: Deep blasting, Removal of topsoil and vegetation, and Mass replacement.
In deep blasting, rock is drilled and blasted to a level that lies below the final unloading level. For deep blasting, we can choose between several design types. In case of roof fall, the depth applies at the centerline unless a reference surface is given.
A = Depth
We refer to the dialog help for more detailed description.
Vegetation and topsoil are usually materials with little bearing capacity and will therefore be removed in many contexts during road construction, for example with low fills and sloping side terrain. Topsoil layers are normally scraped off (preserved) when the materials can be used to cover slopes and ground leveling surfaces.
Materials with little bearing capacity under road constructions will in most cases be replaced with, for example, stone materials. Typically, mass replacement will be performed when the ground consists of peat, strongly humus-containing fine-grained soil types, or soft clay. The materials are excavated down to rock or solid ground.
Removal of topsoil and vegetation and mass replacement function in the same way, meaning we can have the same design types. We can have situations with only topsoil or only mass replacement or a combination of both. Correct construction requires that the physical layers exist.
A* = Topsoil/vegetation layer, B* = Replacement material
We refer to the dialog help for more detailed description.
Superstructure¶
In the superstructure table, we can have many superstructure templates, for example one for soil and one for rock. Each superstructure template is described with up to 8 layers, and only intermediate surfaces (surface group 0-3) can have superstructure.
Superstructure with multiple layers
We can choose between simple and extended superstructure. Extended superstructure (which is VIPS-compatible) supports, among other things, stepping, inner fill slopes, and transitions in the superstructure.
We refer to the dialog help for more detailed description.
We use the table for special leveling to define leveling (the boundary between substructure and superstructure) independent of the road surface. If no data is defined, leveling will automatically be placed parallel to the road surface, according to the thicknesses given in the superstructure table.